1-sided
When a polygon is created, unless otherwise set up, it will have only one
side. If you were to look at a playing card, it has a front and a back.
A 1-sided polygon only has a front, and therefore only one surface normal.
2D
map
Two-dimensional map consisting of either a bitmap or a procedural map.
An object using a 2D map needs texture coordinates. See UV for further
details.
2-sided
Like a playing card. A polygon that has a front, and a back, is 2 sided.
A 2-sided polygon will have two surface normals, facing opposite directions.
3D
A three-dimensional medium, display, or performance, especially a cinematic
or graphic medium in three dimensions.
3D
Accelerator Card
A graphics card specifically designed for 3D graphics. LightWave uses a
system of 3D graphics called OpenGL and your graphics card must support
this.
3D
map
Three-dimensional map either built up from multiple layers of bitmaps or,
more often, generated in three dimensions with a procedural texture. These
are algorithms that can generate 3D maps resembling marble or wood, and
when applied to an object, the grains of the marble, and the fibers of
the wood, will be correctly mapped to the surface in all three dimensions.
If you split a 3D-mapped cube in two halves, the cross section surface
will match the neighboring faces. A 3D map does not require texture coordinates.
3D
object
Anything with a position and a representation in 3D space. Some objects
have a special role, for instance a camera or a light, while others serve
as controls for other objects, for instance splines or manipulators. The
most common 3D objects are geometric objects, which can be classified
according to whether they are polygon meshes, surfaces, curves, implicit
objects, or nulls.
3D
Shutter Glasses
3D glasses made with electronic liquid crystal shutters. They are powered
by the computer they are attached to and use this power to turn on and
off the liquid crystal in each of the lenses creating a 3D effect, instead
of the usual 2D display a computer monitor can offer.
3DS
Aged file format used by Autodesk 3D Studio and discreet 3d Studio max
for three-dimensional scenes. It contains geometry, textures, lights and
cameras as well as animation data.
Absolute
coordinates
The location of a point in terms of distances and/or angles from a fixed
origin. See Relative coordinates.
Adaptive
supersampling
A way of antialiasing the surface of an object by decreasing the oversampling
rate for those pixels that do not require the oversampling. The results
of adaptive supersampling are slightly more localized, and the computing
time is often shorter than other sampling methods.
Additive
mixing of colored light
There are two sorts of mixing of colors. One is called additive, or sometimes
transmissive and refers to the fact that the more red, green and blue
you add together the nearer to white your final color. This is the normal
light scene for LightWave or other graphics packages with output mainly
through the medium of a screen. Subtractive mixing indicates that the
fewer colors you mix the nearer to white you are and is used for reflective
color, such as printed material.
Additive
opacity
Type of opacity that adds the background color to the material's color
of the transparent object.
Aggregate
Object
An object that is made up of a number of other objects. A normal aggregate
object will be made up of primitives. A more complex aggregate object
may be made up of primitives, other aggregate objects, or both.
Algorithm
A problem-solving method that involves using a multi-step process.
Aliasing
When referring to pictures, aliasing is the effect that occurs when a line
looks jagged instead of smooth because of a contrast in colors. Usually,
you can tell when this happens because the line between the colors looks
very jagged, as if it were a flight of stairs, in fact it is often referred
to as a "stairstepping" effect. For contrast, see antialiasing.
Alpha
Channel
One of the four channels (or components) of information that make
up every pixel in an image. There are three channels for red, green, and
blue (RGB) and one alpha channel. The alpha channel is really a mask -
it specifies the transparency of each pixel, which allows portions of
the foreground image to reveal the background when two images are overlaid.
Alpha
matte/image
Alpha matte/image generally refers to an image where the brightness of
each pixel is used to cut or partially dissolve out another image. These
are generally grayscale or black-and-white images, but the brightness
values can also be extracted from a color image.
Ambient
component
Part of the reflection-illumination model. A common surface shader parameter
that adds consistency to the color of an object's surface to simulate
an ambient light that reaches all points in a scene. An ambient value
is determined for individual surfaces. Scene ambience is multiplied with
an object's ambient color. If the scene ambience is set to black, nothing
alters the ambient color of an object except, of course, a light. The
careful balance of ambient and direct light sources is the key to convincing
lighting. Global illumination is an alternative to ambient light that
is more accurate but takes longer to render.
Ambient
map
Allows manipulation of the ambient component of an objects reflection-illumination
model. Usually the ambient component is given a value near that of the
diffuse component.
Ambient
Light
All-directional light illuminating every object uniformly from all
sides.
Anaglyph
Moving or still pictures in contrasting colors that appear three-dimensional
when superimposed. Anaglyph works well for printed matter or computer
display, but color problems inherent in television displays (both PAL
and NTSC) result in poor 3D broadcasts.
Anamorphic
Distort
An option referring to the width of a lens flare. When selected, the larger
the distort factor, the wider the lens flare will become.
Angle
of incidence
The relative angle between a lit surface and the light source. The more
the surface is turned away from the light source, the less light it receives
and the darker it becomes. When the angle of incidence is 90 degrees,
the light shines directly on the surface and it is illuminated with maximum
intensity
Animate,
Animation
The movement of elements through time and space. Also, the process of creating
and recording images that change over time. Everything in a scene is represented
by numeric values and, as such, animation is also the process of changing
these values - position, color, or any other property - over time. A method
of creating the illusion of life or movement in inanimate objects or drawings.
Through animation the artist’s drawing comes to life. The most well known
works are cartoon comedies, like Ren & Stimpy or The Simpsons, for
example.
Animatics
Preliminary animated versions of a final video or film presentation.
Animation
Channel
Animation Channel refers to the different position, rotation, and scaling
settings an item can have in Layout. It can also refer to other envelope
elements like light intensity. See also motion channel.
Annotation
The process of inserting text or a special note, explanation or to provide
relevant detail to a surface, a rig or a point in your scene in LightWave.
Anti-aliasing
A method for blending harsh contours and preventing staircasing or stairstepping.
It is achieved by taking the surrounding areas into account when assigning
a color value to pixels lying on an object's contour.
Antisymmetry
surface restraint
The restraint of a surface tangent to the surface. This implies
that the structure is symmetrical about this plane, and the load on the
implied symmetrical part is equal to, but in a direction opposite to,
the modeled part.
Aperture
The opening size of a camera lens. The greater the aperture, the smaller
the depth of field and the greater the amount of light entering the lens.
API
abbreviation for application programming interface.
Arc
Regularly curved open element that has a constant radius around a single
center point. A section of a circle.
Area
light
A special kind of point or spotlight. The rays emanate from a geometric
area instead of a single point (entire surface uniformly emits light).
This is useful for creating soft shadows with both an umbra (the full
shadow) and a penumbra (the partial shadow).
Array
A set of elements put together into a single entity. A pixel array is an
ordered set of colored elements used for display purposes. In a 3D program,
the array tool is usually used to create ordered copies of an object within
3D space. This tool is so named because it creates arrays of objects (creates
an ordered set consisting of multiple copies of the same object).
Aspect
ratio
A description of the proportion of an image by comparing its width to its
height. 35 mm slides have the aspect ratio of 4:3 (1.33:1). Images become
distorted if forced into a different aspect ratio during enlargement,
reduction, or transfers. It should not be confused with the pixel aspect
ratio, explained further on.
Atmosphere
In LightWave, a volumetric effect that simulates reduced visibility in
air over distances.
Attenuation
When light travels through air its strength diminishes with the distance.
The further the light travels, the dimmer the light. In real life, the
light attenuates by the inverse square of the distance. This means that
if attenuation is turned on for a light only the geometry in its proximity
will be lit. Not only is this more realistic for your renderings, it also
helps speed up rendering time since only the geometry close enough to
be affected by the light needs calculation time. See also Decay.
AVI
A popular file format that combines video and audio. It stands for Audio
Video Interleave.
Axis
of Motion
In 3D space, the line that an object follows during movement.
Axis
of Rotation
In 3D space, the line that an object rotates around.
Axis,
Axes
The reference for describing the origin and position of an object
in space, displayed by intersecting straight lines. By using two axes,
a plane is determined; for example, the XY plane is defined by placing
the X and Y axes so that they intersect at the global center (point of
origin). Three dimensions are determined by using three axes: X, Y, and
Z.
B
rep
Slang for boundary representation
Backface
culling
A process included in most 3D graphics pipelines, backface culling eliminates
triangles facing away from the camera. This is most efficiently performed
by checking the orientation of the triangle normal in relation to the
camera. The technique ignores geometry seen from behind so that only the
fronts of objects that are facing the camera are rendered. Both faces
of an object are rendered by default; that is, the ones whose normals
are facing the camera as well as those that are not. You can choose which
faces of the object you want to render as part of the rendering options:
front, back, or both faces. Back culling (rendering only the front) can
improve performance because less geometry needs to be rendered.
Backface
elimination
See backface culling.
Background
Color
The color that occupies all space not occupied by text, images, or any
other objects. By default LightWave's background color is black.
Ball
Another name for a sphere. Basically, a ball is a 3D circle or oval created
by user-defined dimensions and settings.
Bandwidth
How much information a network can carry. Think of the network as a highway,
and each message as a car. The more lanes in the highway, and the higher
the speed limit, the more traffic it can carry. So the wider the bandwidth
of a network, and the faster its speed, the more information it can carry.
Banking
This is when an object following a path rotates about the path when it
changes direction.
Bank
Shot
A shot in billiards in which the player causes the cue ball or an
object ball to rebound off a cushion. A shot in basketball in which the
ball glances off the backboard before reaching the basket. Also a shot
fired during a heist.
Barn
Doors
The flaps on the front of a movie light to assist in limiting the beam
of light.
Baud
Bits per second. Hence kilobaud or Kbaud, thousands of bits per second.
The technical meaning is `level transitions per second'; this coincides
with bps only for two-level modulation with no framing or stop bits. Most
hackers are aware of these nuances but blithely ignore them.
Bend
To deviate from a straight line or position: The lane bends to the right
at the bridge. To assume a curved, crooked, or angular form or direction:
The saplings bent in the wind.
Bevel
A method of eliminating sharp edges from objects by extending an object’s
faces.
Bezier
Curve
A technique for creating curves that was attributed to and named after
a French engineer, Pierre Bézier, who used them for the body design of
Renault's cars in the 1970s.
Bilinear
Filtering
Blurring the pixels in a bitmap when it is zoomed in so that it seems smoother
than it really is
Bilinear
intensity Calculation
A high-speed algorithm for generating shaded faces. Used in Gouraud
shading and Phong shading
Binary
Space Partition
Also known as BSP, this is a technique used in real-time rendering for
resolving in which order polygons should be drawn. The technique requires
that a so-called BSP tree is built before the scene may be rendered. As
this build process is very costly in terms of execution speed, BSP trees
cannot usually be calculated in real-time and thus essentially only support
highly complex yet static 3D worlds
Bit
The building blocks of computer data. Has either the value of 1 or 0 (current
or no current). Bits can be grouped together to carry larger values.
Bitmap
Two-dimensional monochrome raster image. A bitmap is a black and white
image marking boundaries. It is often used for clip maps in LightWave.
Blade
A thin plane placed in front of a light to cast a shadow, taking light
off of an object. A device to create a shadow.
Blending
The mixing of two (or more) textures into one final texture that is displayed
in rendering, or the final step in making a margarita.
Blitting
The copying of a virtual frame buffer to the displaying screen.
Bone
Hierarchy
Bones can be arranged to build a Bone Hierarchy, also called a Skeleton.
The hierarchy defines how the movement of one bone affects other bones
(up and down the hierarchy). If you then also add Constraints to the bone
hierarchy, you have a Rig.
Bones
The basis of movement for a model. Bones define parts of a model and how
they move in relation to each other. Bones can be created in any object,
even those which would normally be considered to be inanimate, to give
life to that object and make it move smoothly.
Boolean
A mathematical system developed by George Boole that expresses logical
relationships between things. The results in a Boolean operation can be
either true or false. Boolean is used in 3D to add, subtract, and other
operations that involve Boolean calculations.
Boolean
operations
A modeling technique that uses two objects that are overlapping to create
a new object. There are three kinds of boolean operations: subtraction,
union and intersection. By taking the first shape and subtracting/unifying/intersecting
it to the second - a new shape is created.
Boom
shot
A camera move. Usually describes a shot in which the camera is mounted
on a crane. The camera can move in all axes of movement.
Boundary
Representation
A polygonal mesh representation. A polygonal mesh is, most commonly, a
simplification of a shape using facets to describe curvatures. Its surface,
or boundary, is built up from several faces that describe the shape. If
it is a polyhedron the polygon model can be identical to the shape, whereas
an organic shape is represented by a more or less simplified version that
mimic the curvature using facets with variable density.
Bounding
Box
A cubic shape that exactly circumscribes a (more complex) 3D model and
is used to optimize three-space calculations like ray tracing. By representing
a more complex shape with a box, possible ray intersections can be investigated
much more swiftly. Also used to represent complex objects for proxy animation
and setup to speed up operations.
Bounding
Volume
A way of speeding up ray tracing operations involving intersection calculations,
by inscribing a complex mesh in a considerably less complex shape like
a box or sphere. Often used when rendering must be done in a short amount
of time. Instead of having to check the intersection of a more complex
mesh, like a space ship or a teapot, the bounding box works as a stand-in,
with the same maximum height, width and length as the mesh it substitutes
for. Therefore a possible ray intersection can be either ruled out (if
the ray doesn't pass through the bounding box, it doesn't pass through
the mesh either), or let a more time-consuming algorithm take over working
with the complex mesh instead.
Box
Another term for a cube. This is a six-sided 3D object that can be thought
of as a 3D square or rectangle. Boxes are created based on user-defined
input as to the dimensions and locations desired.
BSP
abbreviation for Binary Space Partition.
B-Spline
A free-form curve that is defined with parameters in which each
separate vertex on the curve has an influence over a portion of the curve.
In 3D, B-splines allow a user to control a curved line on two axes at
once.
Bump
Array
See also: array. The purpose of a bump array is to create an ordered series
of bumps in a surface. This tool means exactly what its name implies -
an array of bumps.
Bump
Map
Creates the illusion of three-dimensionality of a surface (protrusions
and cavities) by recalculating the normals of the object, without changing
the mesh itself. It is very common in 3D renderings and suitable for creating
effects like wrinkles, creases, crumples, cracks, seams etc. The silhouette
of a bump mapped object is a give-away since, in these areas, it is obvious
that the mesh is left unaffected (if trying to create an orange by using
a perfect sphere with an orange peel texture applied to it for bumpmapping
will still have a impeccably round silhouette). In LightWave areas in
a bump map that are black are unaffected and areas that are white are
raised.
Byte
8 bits. Multiples of bytes make up the terms kilobyte (1024 bytes), megabytes
(1024 kilobytes) and gigabyte (1024 megabytes).
CAD
Computer Aided Drafting (or Design); A system that lets a designer use
a computer screen instead of a drafting table to make plans and blueprints.
Designers can use CAD for anything from the largest building to the tiniest
screw.
CAM
Computer Aided Manufacturing; the process of using a computer to create
a physical product from a computer-created design. CAM is usually used
to control robots that perform tasks that would be tedious or dangerous
to human workers. See also Rapid Prototyping.
Camera
An apparatus for taking photographs, generally consisting of a lightproof
enclosure having an aperture with a shuttered lens through which the image
of an object is focused and recorded on a photosensitive film or plate.
Nowadays, young technobods also use digital cameras, which use CCDs to
focus light and create a digital picture that can be seen and transferred
to a computer immediately. In LightWave terms, the camera is the conduit
through which your objects and scenes are turned into still images or
animations.
Capping
Surface closing the upper and/or bottom side of an object such as a cylinder.
Cartesian
Coordinate
A mathematical representation of Euclidean space. Every point can be described
by three coordinates (X, Y, Z) representing the position along the orthogonal
X, Y, and Z axes. The point (0, 0, 0) is called the origin, which is the
global center of the 3D world.
Cartesian
Space
A space in which positions are denoted by a three-coordinate system
(x, y, and z coordinates) relating to a central origin (0,0,0).
Catacorner
slanted across a polygon on a diagonal line; "set off in a catty-corner
direction across the vacant lot". syn: cata-cornered, catercorner,
cater-cornered, catty-corner, catty-cornered, kitty-corner, kitty-cornered
Catawampus
All outtawhack.
Caustics
Light pattern created by specular reflection or refraction of light, such
as the patterns of light on the bottom of a swimming pool, or light through
a glass of wine.
CD
Abbreviation for Cadmium. A soft, bluish-white metallic element occurring
primarily in zinc, copper, and lead ores, that is easily cut with a knife
and is used in low-friction, fatigue-resistant alloys, solders, dental
amalgams, nickel-cadmium storage batteries, nuclear reactor shields, and
in rustproof electroplating. Atomic number 48; atomic weight 112.41; melting
point 320.9°C; boiling point 765°C; specific gravity 8.65; valence 2.
Also used to designate compact disc storage media.
Center
of Projection
The point in perspective projection where all projectors intersect.
Center
of the World
Is the absolute center of a 3D space, represented by X, Y, and Z points
(0, 0, 0). Also referred to as the Origin.
Center
Point
A point that represents the center of an object. This point is used
in some programs for a point of reference for rotation and position. The
center point of a polygon is where the line representing the normal comes
out from.
Chamfer
To cut off the edges of the geometry with a planar cut, creating a more
blunt shape, typically at a 45 degree angle; A beveled edge or corner
between two intersecting lines or surfaces.
Child
An object whose movements are influenced by another object, called the
“parent”.
Chord Length Parameterization
See non-uniform parameterization
Clean
Modeling
Refers to the practice of removing geometry from a model that is not wanted
or needed. Also refers to the use of proper geometry construction techniques,
such as creating continuous surfaces, minimizing narrow faces, and avoiding
small corner angles, that facilitates downstream processes.
Clipping
More often than not, much of the graphics drawn for a specific scene does
not fit into the viewport of the camera. Accordingly, those which fall
outside of the viewport must be clipped so as they are not drawn. Depending
on the nature of the application, there are two kinds of clipping: 2D
and 3D. The earlier simply compares each pixel against the extents of
the rendering viewport, while the latter technique uses the six sides
of the view frustum to determine whether a 3D vertex is inside the viewport
or not.
Clone
This tool creates copies of an object based on user-defined parameters
for offset, motions, morphing, shadows, etc. This tool can be used to
make ordered sets of objects, but is different from the array command
because not all of the new objects will be exactly the same as the original.
Cloud
of Points, or Point Cloud
A set of x-y-z coordinates obtained from a 3D scanner or digitizer.
The data can then be turned into a continuous surface and used as a 3D
model.
CODEC
Short for “compressor/decompressor”. This is the term used to reference
the way that software programs handle different movie files, such as Quick
Time, AVI, etc. The CODEC can control image quality, and can assign the
amount of space given to the movie file. First, a multimedia publisher
uses a codec to squeeze more sound and video into less file space. These
compressed files are easier to fit on a CD-ROM and transfer to your computer.
Then, your computer uses a codec to expand these files back to their original
size and replay them on your screen.
Coincidence
Refers to geometry that occupies the same spatial location. For example,
coincident vertices are points that occupy the same x, y, and z coordinates.
Coincident lines can have differing lengths while one occupies the same
location as the other.
Color
Bleeding
When the color from one surface reflects onto another surface.
Color
Depth
The number of bits used to represent a color. For example an 8-bit image
uses 2^8=256 colors. The bits build up the three primary colors red, green
and blue.
The bits are
divided into red, green and blue (optionally an alpha channel as well).
For example a 16-bit color could look like this R: 4-bit (16), G: 4-bit
(16), B: 4-bit (16), Alpha: 4-bit (16) - together they add up to 16-bits.
The number of bits can also be unevenly divided (R:5, G:5, B:5 Alpha:1).
This is why
a GIF (max 8-bit=256 colors) only sports 128 colors if it is transparent
(1 bit is used to represent transparency in the alpha channel, 7-bits
= 7^2=128).
The following
table indicates the number of colors an image can have.
8-bit =
2^8 = 256
16-bit = 2^16 = 65536
24-bit = 2^24 = 16 million
32-bit = 2^32 = 4.3 billion
You should
also be aware of FP, or HDR images.
Color
Model
A system used to specify colors. In LightWave, you can set color according
to the following color models: RGB (red, green, blue), HLS (hue, lightness,
saturation), HSV
(hue, saturation, value) or integer values.
Color
Keying
An old technique of combining two images by replacing one color of the
destination image by the corresponding pixels of the source image.
Column
Interleaved Format
The 3D image format used by the VR-4200 projector. Left and right
view image data are encoded on alternate columns of the display.
Compiled
Vertex Array
Array of geometry data on a vertex level that is optimized (compiled) for
faster access by the graphics card. (Note that this is an OpenGL term,
and is known by other names in other APIs.
Compositing
A layering technique that places one image on top of another, properly
taking transparent pixels, apparent depth, shadowing and other elements
that make up an image into account.
Concentric
Having a common center or origin point with varying radii.
Cone
angle
The angle at the peak of a cone.
Conic
Element having the form of a cone.
Conic
section
Curve formed by the intersection of a plane with a cone.
Constraints
Values in a geometric model that define relationships, i.e. a line is tangent
to a circle. Constraints are often used to drive parametric or variational
geometry-based systems; the algorithms used to work with constraints are
known as constraint management.
Continuous
LOD
Short for continuous Level-Of-Detail, this method is based on the observation
that 3D objects located far off in the distance may be approximated by
simpler versions without loss of visual quality, thus increasing the rendering
performance. The "continuous" refers to having the algorithm
constantly recompute the detail level of the 3D object depending on the
distance to the camera instead of having a pre-computed set of objects
to choose from. Computationally expensive, this method is most often used
in height field rendering applications. LightWave can approximate continuous
LOD by using an Object list.
Convex
Volume
A convex volume can be defined as a volume whose every corner can be visible
from all other corners in the same volume. Another way of defining the
convexity is that all faces in the volume will be lit by a point light
located anywhere within the volume.
Cookaloris
A device put in front of a light, to break the light up. Common cookalorises
look like leaves on trees, or blinds on windows.
Cookie
A small, usually flat and crisp cake made from sweetened dough. Also, slang
for a cookaloris.
Coons
Patch
A free-form surface that is determined by the four curves that define its
edges.
Coplanar
Refers to two or more entities that lie on the same plane. Two planar surfaces,
for example, that lie on the same 3-dimensional plane are considered coplanar.
If these coplanar surfaces share a common edge, it is recommended that
they be joined into a single surface.
Cross
Product
Using two vectors to calculate a normal of those two.
Cross-Section
A view of the interior of an object as it is sliced along a plane.
Cubic
Image Map
One of the many methods of applying a texture to a surface. This method
applies the texture to an object as it would apply the texture to a cube.
There are many other methods of texturing objects, such as Planar and
Cylindrical image mapping.
Curvature
Continuity
A curvature continuity with smooth transition of the edges of two
meeting surfaces (the highlights of the two surfaces blend together seamlessly,
forming the illusion of a single shape). If a curve (or surface) has tangent
continuity and both the 2D curves (or 3D surfaces) have the same radius
a very smooth transition is created with curvature continuity. Curvature
is defined as 1/radius. Hence, small radius equals high curvature
Curve
In computer graphics, there are different ways of representing a curve,
for example using NURBS and Bezier curve, so see those terms, okay?
Curve
Parameterization
See parameterization
CVA
Abbreviation for compiled vertex array.
Cylindrical
Image Map
One of the many methods of applying a texture to a surface. This method
applies the texture to an object as it would apply the texture to a cylinder.
There are many other methods of texturing objects, such as Cubic and Planar
image mapping.
Decay
Phenomenon where the light intensity decreases with the distance. The further
away from the light source, the less intense are its rays. In the real
world the decay is proportional to the inversed square of the distance
(quadric decay), but there is also directional (one-dimensional) decay
(slower than in real life) as well as cubic decay (faster than in real
life). See also attenuation.
Decompression
Process of returning a compressed file to its full size (or a diver to
the surface if he has been on a particularly deep dive).
Default
unit
The Default unit is the unit of measure (ex. meter, feet, etc.) that is
assumed, usually when no unit of measure is entered with the numeric data.
In Layout, it is determined by the setting on the General Options tab
of the Preferences panel. In Modeler, the setting is on the Display Options
panel.
Depth
buffer
Same as a Z-Buffer.
Depth
Cueing
The process of reducing the apparent sharpness of an object the farther
away it is from the viewer or camera. This often enhances the perception
of depth.
Depth
of Field
The total distance, on either side of the point of focus, which, when viewed
from an appropriate distance, APPEARS sharp in the final print.
Depth
Sorting
Sorting all triangles in the world depending on diminishing depth (lower
and lower z-value) so that when they are rendered, the triangle closest
to the viewer is obscures those behind it.
Deskew
Process used to remove skew or distortion through a small angle rotation.
Diffuse
Component
Part of the reflection-illumination model. The diffuse is concerned
with the amount of light that is reflected back.
Diffuse
Light
A component of the reflective model that is the result of direct illumination.
Diffuse
Map
Replaces the diffuse component of the reflection-illumination model, basically
giving the illusion of being painted onto the surface. To create a material
resembling wood or marble, this map is used. Generally, when you talk
about the "texture map" in an application, this is the map actually
referred to.
Dimension
A measure of spatial extent, especially width, height, or length.
Directional
Light
Another name for a distant light.
Director
of Photography
The person on a movie set that determines how to photograph the movie.
Disc
A shape that is referred to in mathematics as a cylinder. This shape is
composed of two circular or oval-shaped bases and the space contained
between those bases. In other words, a disc is like a stack of circles
with set parameters defined by the user.
Displacement
Map
Can be used to modify the actual mesh (as opposed to the bump map)
to create wrinkles, creases, crumples etc. The displacement map will need
a more complex mesh to create the same effect as bump mapping, but has
the advantage of allowing more thorough close-ups, since the surface is
actually deformed and not just simulated as being so.
Display
Types
Ways of displaying objects in a viewport. Display types are available
only for geometry views. The available display types are Bounding Box,
Vertices, Wireframe, Front Face Wireframe, Shaded Solid, Textured Shaded
Solid and Textured Shaded Solid Wireframe. Display types do not determine
the quality of the final render.
Distant
Light
A light with color, intensity and direction. All rays emitted from a distant
light are parallel, and therefore it has no obvious source.
Distant lights
can be used to simulate point lights from a great distance (whose rays
can be approximated to be parallel) like for example the sun. The intensity
from a distant light does not decay.
Dithering
Creating the impression of having more color on the screen than there actually
are by plotting pixels (with a limited amount) of different colors next
to each other.
DOF
Abbreviation for depth of field.
Dolly
To move the camera along its line of sight (in a straight line following
the imaginary path between the actual camera and its target point).
Dongle
A hardware lock used to prevent the piracy of LightWave. A common question
from people who have pirated LightWave is "what's a dongle?"
Dopesheet,
Dopetrack
Two animation tools in LightWave that allow the user to better organize
his keyframes.
Dots
per Inch, dpi
In a bitmapped image, the number of dots that exist within each
inch of the image. This number remains constant, so when you make an image
larger, the quality decreases, but when you make the image smaller, it
appears to increase.
Double
Buffering
This is the process of using two frame buffers for smooth animation.
While the image of the first buffer is being displayed, the graphics controller
can use the second buffer to build or render the next image. Once the
second image is completed, the buffers are switched. Thus, the result
is the appearance of smooth animation because only complete images are
displayed, and the process of drawing is not shown. You can often now
see Triple buffering in graphics cards to allow an extra buffer for the
next image in case there is a problem.
DP
Abbreviation for Director of Photography.
DVD
A high-density compact disc for storing large amounts of data, especially
high-resolution audio-visual material. Abbreviation for digital video
disc or digital versatile disc. A DVD used solely for a computer is commonly
referred to as a DVD-ROM.
DWG
AutoCAD native file format. It can contain 3D data, but is hard to convert
to a LightWave-native format because of its construction. A DWG file is
parametric, that is to say it does not contain the objects themselves,
but rather instructions on how to build the objects. This makes it hard
to translate if you do not possess a license of AutoCAD. The solution
is to either get one or get your client to supply you the object in a
different format, preferably OBJ.
Easing
The reduction in the acceleration or deceleration of motion to present
a smoother, more continuous movement. The shape of a function curve can
reflect this when using a spline interpolation.
Edge
A straight line connecting two points on a polygon. LightWave does not
allow you to select edges as discrete elements of a 3D object, but selecting
the aforementioned two points does the job.
Edge
Loop
A particular method of modeling organic shapes with the edges of polygons
creating a loop or a flow around circular features around the eyes and
the mouth for example.
Environment
Map
Map often used to simulate (faking) reflection of the surrounding world
without using ray tracing.
Euler
Angles
Euler angles are one of the simplest methods of representing 3D rotations,
and generally also the easiest to visualize. An object's rotation can
be specified in terms of its yaw, pitch and roll, or rotation around the
Y, X and Z axis, respectively. Euler angles suffer from singularities
in the form of so-called Gimbal lock, however, and are also difficult
to smoothly interpolate for keyframe animation
Expression
Mathematical expressions that allow you to change the animation of an object.
You can also create constraints between objects using expressions or create
conditional animation. Expressions are very powerful for creating precise
animation and to create automated animation of things such as wheels.
External
Attributes
The position of the camera and the direction it's pointing.
Extrude
Creating a three-dimensional object from a two-dimensional shape by adding
a third dimension to it. You can also do this along a motion path or spline.
Face
The shape made up by the bounding point making a polygon. Faces can have
as many vertices as wanted, but only polygons having a shape of three
or four vertices can be made into sub division surfaces.
Face
Normal
Also just known as the normal, this is a line perpendicular to the face
that also describes which way the face is pointing in a one-sided polygon.
Falloff
The volume starting at the outer rim of a spotlight's hotspot, decaying
from full intensity at the start to zero intensity at the outermost rim
of the spotlight. The less the difference (in angles) between the hotspot/falloff,
the crisper the shadows. If the falloff angle is much larger than the
hotspot angle, the boundaries of the area lit up by the spotlight will
be fuzzy. NOTE: in real-life, you are unlikely to find lightsources with
a hotspot angle close to the falloff angle. Normally, the edges of shadows
are not too crisp, but smooth, so a word of caution might be in place
to prevent overusage of sharp edged shadows.
Field
of View
(FOV) The angle of the view frustum. The wider the FOV, the more you see
of the scene. Human eyes have a FOV of about 50 degrees, and normally
virtual reality application use similar values to resemble real life.
Field
Rendering
An option that causes the program to render two interlaced fields of information.
This is in contrast to rendering only one (full frame) and makes moving
objects appear to move more smoothly. Used for projects that will play
back on television monitors that display 50 or 60 interlaced frames per
second. Fielded animation is not useful for animations designed to be
display on computer monitors. See Fields.
Field
Sequential 3D Video
The most common format for 3D video. Left and right image data are encoded
on alternate field of the standard video signal.
Fields
Interlaced images (video) consist of two fields that are combined into
one frame. Each field contains half the scan lines (either even or odd)
and is a separate pass. This is more common to render to for TV broadcast.
Horizontal movement of items will strobe without rendering to fields.
Fill
Light
Additional light sources assisting the key light in a scene. Usually they
are less intense than the key light and created using point light or spotlight.
Fillet
To round off the edges of an object with a round shape. Think "router",
use "Rounder" in Modeler to achieve it.
Fill-rate
The amount of pixels from a texturemap (texels) that is rendered per time
unit. Measured in texels/second.
Filter
Opacity
Type of opacity that uses a color to simulate object opacity.
Finger
A small strip placed in front of a light to cast a discrete shadow.
FK
Abbreviation for forward kinematics.
Flag
A device placed in front of a light to create a shadow. A flag is large,
to remove light from a large area.
Flat
Shading
Shading technique where all individual faces in a mesh are assigned a single
color value based on the orientation of their face normals.
Flatness
Flatness is used as a threshold in determining if a polygon is non-planar.
A flatness of 0 percent means the polygon is absolutely flat. Flatness
is computed as percentage deviation from a triangle (the “ideal plane”)
formed from the first two and last vertices of a polygon. All of the other
points are measured relative to this plane. The largest deviation is divided
by the total size of the polygon to get a percentage that is the flatness
value. For example, if a polygon is 1 meter wide, 5% flatness means that
no point will be outside the ideal plane of the polygon by more than 5
millimeters. (1 x .005)
Floating
Point (FP) images
Refers to images that do not use standard color depth models to represent
the colors contained in them, but rather an expression of the floating
point value of a color changing from 0 for black up to 1 for the brightest
point in the image. A mid-gray in such an image would be represented by
R: 0.5, G: 0.5, B: 0.5.
Focal
Length
The distance between the lens and the light-sensitive surface on the backplane
(the film in real-world cameras). The lower the focal length, the more
of the scene is visible. Focal lengths less than 50 mm is called wide
angle, while lengths greater than 50 mm is referred to as telephoto lenses.
The longer the lens, the narrower the field of view. Distant details becomes
more visible. The shorter the lens, the wider the FOV. More of the environment
is visible in the rendered image. To simulate the human eye, you can use
values of about 50 mm.
Fog
Simple yet effective graphical effect most often used in real-time graphics
to obscure the far plane, thus bounding the viewing distance of the application.
There are essentially three types of fog: table-based, vertex-based, and
volumetric. Fog values may also follow linear or exponential curves. It
can also be found in graveyards during a full moon on Halloween.
Foreground
Image
The image closest to the camera.
Foreshortening
The apparent effect of viewing an object on its long axis that makes it
seem shorter. For instance, an arm pointing directly at the camera seems
to lose its length as does a road going directly away toward the horizon.
Formula-defined
Shapes
Refers to shapes that are defined by using one or more equations. This
includes complex shapes such as aesthetic bottles or simple shapes such
hyperbolic paraboloids, oblate spheroids, prolate spheroids, or ellipsoids.
Forward
Kinematics
Figure positioning by joint angle specification. Like posing a toy action
figure.
FOV
Abbreviation for Field of View.
FPS
FPS stands for Frames per Second. This is the main a unit of measure that
is used to describe graphics and video performance.
Frame
A single complete picture of an animation. A frame is a static image which,
when followed by other static images sequentially, gives the illusion
of motion. You can render to frames or to fields. One film frame is 1/24th
of a film second. One video frame is either 1/30th for NTSC or 1/25th
for PAL.
Frame-buffer
The memory a computer uses to hold one or more frames for later use.
Frame-rate
The speed at which a frame of animation is shown, usually expressed in
frames per second. US TV is typically 29.97 frames, European is at 25
frames per second and movies are projected at 24 frames.
Freeze
To convert from vector or interpolated geometry (splines, NURBS, subdivision
surfaces) to pure polygons. Even if the renderer supports NURBS or subdivision
surfaces, this freezing happens at render time, and is usually definable
to the level of polygon creation by the user.
Frustum
The part of a solid, such as a cone or pyramid, between two parallel planes
cutting the solid, especially the section between the base and a plane
parallel to the base. See view frustum.
Fudge
Slang, to fake it, or to stretch the normal rules.
FX
Shorthand term for effects.
GCore
(Geometry Core)
The engine in LightWave that handles all animation and modeling tools.
Generic
Primitive
Simple 3D objects that most 3D programs can create easily. These objects
typically consist of spheres, cylinders, cubes and cones.
Geometry
The points of an object. These points are usually seen with objects that
can be rendered. For example, a cube's geometry is composed of eight points.
By this definition, a curve has geometry since it is also composed of
one or more points, whereas nulls have no geometry. Geometry refers to
the positional layout of points and polygons for an object. The mathematics
of the properties, measurement, and relationships of points, lines, angles,
surfaces, and solids.
Gimbal-Lock
What happens when two axes of rotation line up, thereby making 3-dimensional
rotation impossible. Here's an easy illustration, take any object with
neutral rotation (0 degrees on heading, pitch and bank) and rotate in
the pitch 90 degrees. Now, try to rotate in the bank. This is gimbal-lock.
Gizmo
See null object.
Global
Illumination
Unlike the local illumination, this method of generating images supports
effects not only linked directly to the light sources themselves. In real
life, the intensity of a surface not only depends on direct illumination
from the light source itself, but also from indirect illumination from
surfaces being lit. First there is ray tracing that can cast shadows from
one object onto a surface, allow objects to be reflected in shiny surfaces
or refracted in transparent materials.
Then there
is radiosity, the effect of reflected light. If you have spotlights projected
at the ceiling in a white room, the light would bounce back and light
up the entire room. However, this can only happen if the renderer supports
radiosity or other similar techniques, which ours does. Hurrah!
Glossiness
This option affects how spread out across a surface a highlight caused
from a light is. Low glossiness makes a spread out highlight while high
glossiness creates a more central, pinpointed highlight.
Glossiness
Map
An image to control the glossiness of a surface. Bright values in the image
indicate more glossiness, dark values less.
Glow
Optical light effect that looks like a fuzzy disc around the center of
a light source.
Goal
An object used in IK to create a point where an object will always reach
for. This is used to make objects appear to have realistic motion. Also
to score a point in most sporting events.
Gouraud
Shading
Developed by Henri Gouraud in 1971, this is a fast incremental shading
technique using bilinear intensity calculation to create smooth transitions
between the vertices in a triangle. It is most often used for lighting
purposes by computing the vertex normals in the polygon, calculating the
light values for each vertex, and then Gouraud shading the polygon. Even
though it has obvious advantages over flat shading, the facets in the
mesh can still be discerned. The placement of the highlight depends on
the underlying polygons.
Graphical
User Interface
The graphical interpreter between man and computer allows a more intuitive
interaction with the computer. The window maker in UNIX, and Windows for
the PC are both GUIs. This way you don't have to be computer literate
to the same extent as if you should have to type all commands you wanted
the computer to perform.
Greeblies
English slang. This describes the non-such little details on objects, usually
mechanical objects. Those details such can be found on spaceships, in
engine rooms, etc. You can also use the words "didges", "nurnies"
and "doohickies".
GUI
Abbreviation for Graphical User Interface.
Halo
Optical light effect that forms concentric circles around the center of
a lightsource. Often clearly visible around street lights after a rainy
day.
Hidden
Any element that is not shown in the current rendering of the scene but
still exists.
Hidden
surface removal
Algorithm for removing obscured polygons in a three-dimensional view space.
As opposed to the faster algorithm backface culling, the hidden surface
removal algorithm is able to sort out those polygons that are obscured
by another object. Another way of finding an obscured polygon is the z-buffer.
Hierarchy
A way of defining objects in relationship to each other (using a parent-child
or tree analogy). This relationship means that transformations, deformations,
and any other property of the parent object affect all child objects.
This allows separately modeled objects to be used in a scene as a single
functional unit. The movement of a parent affects the movement of the
child, but you can move the child without affecting the parent.
High
Dynamic Range Image
HDRI is an image with a wide intensity range between the brightest and
darkest pixels. In typical 8/24-bit images, the maximum possible intensity
range is 255 times brighter than the darkest gray pixel (with a value
of 1). Natural scenes and images rendered with radiosity can have dynamic
ranges from 10 to 10,000 times greater than this. Recording this information
requires use of an image format with higher precision.
Highlight
Reflection of a light source on an object's surface. The size of the highlight
(the area that shows the light source reflection) depends on the angle.
Consequently, multiple light sources results in multiple highlights. This
is also the specularity.
HLS
color model
Hue, Lightness and Saturation: the three components of the HLS color model.
Hue refers to the position of the color in the spectrum, such as red,
yellow, or green. Lightness is the amount of white mixed in a color, such
as the difference between a pure red and pink. Saturation is the purity
of the color, such as the difference between a pure red and a dusty rose
- low saturation means that there is grayer in the color.
Hotspot
The inner intense cone of light emanating from a spotlight.
HSV
color model
Hue, Saturation, Value: the three components of the HSV color model.
This color model defines the hue and saturation similar to the HLS model.
Value is similar to lightness, as in HLS; however, a value of 1 represents
a pure color when saturation is 1, while a lightness of 1 yields white
no matter what the saturation. In both systems, 0 is black.
Hub,
The
The Hub is a module in LightWave that allows the Layout and Modeler modules
use to synchronize information. It uses the TCP/IP protocol to transfer
information between modules.
Hue
The position of the color in the spectrum that describes the tone or tint
of a color, such as red, yellow, or blue.
HyperVoxel
Voxels are volumetric rendering effects. HyperVoxels are voxels
that are applied to nulls, points, or objects.
IK
Abbreviation for Inverse Kinematics.
Image
instance
A copy or instance of a source image. Each time you use a source image,
an instance of it is created. You can have as many instances of the same
source as you need. You can then edit, crop, or even blur the instance
without affecting the original source image.
Image
Map
An image that is applied to an object's surface.
IMO
In My Opinion.
Incandescence
The emission of visible light by a hot object. In LightWave, this is the
luminosity channel.
Incremental
shading
See interpolative shading.
Indirect
illumination
Light that bounces of one surface and illuminates another surface. This
can only happen if the renderer supports radiosity. Does the LightWave
renderer support radiosity? Yes, of course!
Intelligentities
Intelligentities refer to LightWave's object format. The object format
can contain morphs, multiple layers, and independent pivot points on a
per layer basis.
Intensity
The strength at which the light source illuminate objects in the scene.
Interference
Checking
The process of identifying if and where two or more pieces of geometry
(usually solids) intersect. When moving parts are involved, a kinematics
analysis is used to detect interferences.
Internal
attributes
The properties of the camera such as depth of field and line-of-sight.
Interpolation
The process used to estimate an unknown value between two or more known
values. In animation, interpolation is the process used to calculate values
at frames between two keyframes in a sequence.
Interreflection
When a reflective object reflects another reflective object. For example,
if you place two mirrors in front of each other, the first one will display
the second one, who, in turn, shows the first one. In real-life, there
is virtually no upper limit of how many interreflections that may occur,
whereas in 3D rendering, one must set an upper limit to be able to render
the scene. The default value for LightWave is 16, but it can be lowered
to 0, if desired, or up to 24 at a cost in increased rendering time.
Inverse
Kinematics
The process of determining the motion of joints in a hierarchical 3D object
given the desired start and end points, all the while obeying the laws
of kinematics. Think of it like the strings on a marionette puppet.
IR
Transmitter
A device that sends synchronization signals to wireless shutter glasses.
Isometric
view
Standard view in a 3D design where the top, front, and right side faces
of a cube are equally inclined to the screen surface.
Item
An item in Layout refers to an object, bone, light, or camera.
JPEG
(Joint Photographic Experts Group)
A widely accepted, international standard for compression of color images.
JPS
Stereoscopic JPEG file. JPS refers to a stereoscopic image file format
that is based on JPEG compression. Used by DepthCharge & other stereoscopic
imaging applications.
Junkyard
A special directory used by some studios to hold mechanical and non-organic
pre-modeled parts.
Key,
Keyframe
A marker on the animation timeline that shows that a node's (e.g. an object,
a material or a light) attribute (e.g. position, color or intensity) in
the scene graph has been assigned a new value. Most animation programs
interpolate the node attribute values from one key to the next, creating
smooth transitions - so the user does not have to key every single frame.
See also tween.
Key-light
Dominate light source in a scene, normally created with a spotlight.
Kinematics
The properties of each 3D object that control its transformations. These
transformation properties are used to modify the selected object's scaling
(size), rotation (orientation), and translation (position) in X, Y, and
Z in either local and global space. Although related, kinematics are not
to be confused with inverse and forward kinematics for animation.
Kit-bashing
An expression taken from model making. The practice of using model kits
to give detailing to a larger project. This is still in use. It refers
to the taking of models that you have already made, to use in the creation
of another, perhaps even basically unrelated.
Lasso
One way to perform a selection of point(s), face(s), or polygon(s). This
method involves drawing a loop that encircles all of the objects that
need to be selected.
Latent
surfaces
Surfaces that are no longer visible after a Boolean or intersection operation
because they lie inside or outside the solid.
Lathe
Creating a three-dimensional object from a two-dimensional shape by rotating
it around an axis.
Lattice
Either a way of deforming object using a lattice or a way of creating outlined
geometry.
Layer
A portion of a scene. Each layer consists of an object or multiple objects
that can be edited separately from the rest of the objects in a scene.
A layer is basically a building block for a scene and each layer contains
separate blocks for a final model.
Left-handed
coordinate system
Coordinate system where the positive part of the Z-axis goes away from
the observer (from the screen).
Lens
Part of the camera determining the optical characteristics of the image,
such as wide angle, fish eye and depth of field.
Lens
flare
Optical light effect made up from a number of bright discs. If the
rays from a light source reflects off the surface of a compound lens in
a camera, it can generate star-like patterns on the image. Lens flares
tend to be a cliché of bad CG imagery, probably because of their short
rendering time and flashy appearance.
Level-of-detail
This is a term that is talking about varying the amount of detail in an
object depending on the distance from the object to the camera. Example:
A car for a close-up would need to have every little detail modeled into
it. Chrome, bumpers, body seams, door handles, etc. But that same car,
as seen from a helicopter flying over a highway, might be able to be a
simple cube with an image map applied to it.
Level-of-Detail
control
The ability to vary the amount of details displayed in a graphics image
to improve performance. For instance, at a distance, models can appear
as simple 3D figures, but as users zoom in, a more detailed representation
is presented.
Light
In 3D graphics different types of lights are distinguished: ambient light,
diffuse light, point light, spotlight. There are also different terms
used to simulate material properties is illuminated: ambient component,
diffuse component, specular component. Incident light at a surface = reflected
+ scattered + absorbed + transmitted. Light has a major impact of a rendered
scene, but can be hard to recreate.
Light
source
There are several different sorts of light sources used in 3D graphics
to simulate light: ambient, distant, linear, area, and spotlight. Special
light effects can be recreated such as volumetric light and glow. With
radiosity, an object with a high luminosity value can cast light as well.
Lighting
a scene
One of the ingredients of a nice rendering is realistic lighting. It is
often good to use one single light source (the key light) doing most of
the work, helped out by some additional, less intense lights (fill lights)
that illuminates the background of the rendered object to create a smoother
look. Try to avoid shadows with edges that are too crisp, since this is
unusual in real life due to radiosity.
Lighting
Model
This is a model that uses a mathematical formula to decide what will happen
when light strikes an object’s surface.
Light-map
Luminance map generated (normally rendered) individually for each
polygon and then blended with the texture map to give the impression of
light and shadows falling onto the polygon without having to draw the
effect on the texture itself. The advantage of separating the light-map
from texture map is that if you should want to create a new "mood"
for a scene you can set up new lighting conditions for the scene, re-render
the light-maps and apply them to the mesh again, without having to redraw
all texture maps.
Linear
patterning
The repetitive placement of the active pattern cell along a line, line
string, shape, arc, circle, ellipse, or curve element.
Line-of-sight
LOS has become quite important in modern real-time interactive simulators,
especially for military purposes. To cut down on the polygon count and
increase rendering performance, programmers are often forced to employ
schemes to simplify terrain at large distances. This, however, has the
unfortunate drawback of warping the terrain, something that may make a
difference for long distance targeting purposes. Because of this, modern
terrain rendering algorithms such as ROAM tend to not simplify along the
primary LOS.
Local
coordinate system
As opposed to the world coordinate system the Local Coordinate System is
tied to a specific object. LCS are used, among other reasons, to simplify
the representation of complex objects by using several, different LCSes
as reference points for the object's vertices. It is also easier to transform
the object if you for instance can rotate it around its own "center
of gravity" instead of the origin of the World Coordinate System.
Local
Coordinates
Every object has its own origin, which is subordinate to the world coordinate
system (or other objects that are higher in the hierarchy). Local coordinates
are useful for determining positions of subordinate objects.
Local
illumination
A mathematical model capable of creating imagery where only direct
illumination is considered. Depending on the distance from the lightsource,
etc, each surface in the model can be given a color and intensity. This
does not include shadows, reflections and radiosity.
LOD
Abbreviation for level of detail.
Skin
Creating three-dimensional object from two or more two-dimensional shapes
and then extruding them along a path.
LOL
Laughing out loud
Loop
A continuous playback of an animation sequence.
LOS
Abbreviation for line of sight.
Low-poly
modeling
To model using boundary representation using as few polygons as possible
to speed up rendering and processing time. Common style for games, but
as game processor engines get better, and computers faster, this is losing
ground as an art form.
LScript
This is LightWave's built-in scripting language. LScripts can be installed
and used just like plug-ins.
Lumel
This is short for LUMinance ELement, the lumel is a pixel in a lightmap
which constitutes the color level in a specific area of the texturemap
it is superimposed upon.
Luminance
The black and white information (brightness, sharpness, and contrast) encoded
in a color. The amount of luminance contained in a color is directly proportional
to the amount of light intensity.
Luminance
map
A map that controls the luminosity channel of a surface.
Luminosity
Much like glow, luminosity is a measure of how much light a surface gives
off before any light strikes it. This effect can be used to create an
object that gives off its own light.
Magnet
This tool allows the user to move points in an object as if he or she was
using a magnet. It has an area of falloff where the strength of the magnet
decreases gradually to 0 giving a soft selection effect.
Map
An attribute that can be added to an object's surface to give it a certain
look. Projecting an image so that it covers the surface of an object or
images that affect the way an object looks. There are a variety of different
maps used for to create specific effects: diffuse maps, bump maps, opacity
maps, etc. Maps can be divided into bitmap-dependent texture maps and
procedural maps. The latter categories can, in turn be divided into 2D
maps and 3D maps.
Mapping
The process of making one image conform to the size, shape, and/or texture
of another image.
Material
There is an underlying material in any given surfacing, even though it
might be hidden underneath another texture map. By modifying the properties
of a material it can be made to look like wood, plastic, glass, metal
etc, (hence the name). The material is applied to the whole object. Also
can be referred to just as surface.
Material
properties
The different properties of a material such as the ambient component, diffuse
component and specular component in the reflection-illumination model.
Matrix
What is the Matrix? Much more than a mere programming term, or a movie
with Keanu Reeves. Matrices form the core of linear algebra and are important
tools in most engineering disciplines. In essence a two-dimensional array
of numbers, matrices are often used in transforms of different properties,
such as rotation, scaling, translation, deformation, and much more.
Memory
swapping
The transferring of data back and forth between active RAM memory and disk.
When this happens, it can considerably slow down computing tasks such
as rendering.
Mesh
A really hip way of referring to your objects. Object made up from a number
of triangular faces.
Mesh
complexity
Term for describing the amount of information (amount of vertices, normals,
triangles etc) used to create an object. A higher mesh complexity needs
more memory and is slower to process
Metaform
One of the options used with the Subdivide tools. This feature does not
divide the polygons, rather it renders the edges of the polygons to be
smooth, making the object seem less faceted and cleaner.
MIP-mapping
Using a pyramid structure of a predefined fixed amount of differently sized
bitmaps (original size, original size/2, original size/4, etc) to speed
up rendering time by using less detailed textures for distant objects
(represented by only a few pixels on the screen), and the full-sized version
of the bitmap when the objects is closer to the observer. This way, moiré-pattern
can be avoided.
Mirror
The mirror tool creates an exact mirror image of the selected object. This
tool is very useful for any symmetrical object, including faces, cars,
and airplanes. This tool literally cuts the modeling time of these objects
in half. Can be used to detect vampires.
Modeling
The process of creating a 3D scene consisting of objects and the applying
of mapping to those objects or of posing before a camera, sometimes with
no clothes on!
Moiré
pattern
Optical pattern created due to aliasing. Usually appears as a swirling
pattern along a distant edge.
Morgue
A special directory, used by some studios, to hold already modeled organic
body parts. If you have modeled a good head, hands, ears, feet, etc. there
is no reason to model them again. These models are placed in a "morgue"
for other modelers to draw from.
Motion
blur
The blurring of objects that move while the camera shutter is open, creating
the illusion of movement. Motion blur also prevents strobing caused by
too-rapid of movement.
Motion
Capture
A method used to input live movements into a computer with an external
source.
Motion
Channel
Motion Channel is generally the same as Animation Channel, but refers only
to position, rotation, and scale (i.e., not light intensity.).
Motion
Path
The line an object follows while in motion.
Movements
There are four basic camera movements: dolly, pan, orbit and truck.
Multiplex
The process of taking a right and left image and combining them with a
multiplexing software tool or with a multiplexer to make one stereo 3D
image. It's also where you go to see movies, usually has more than six
screens.
Multi-texturing
Applying two (or more) textures on the same face. For example, a polygon
can have a texture map resembling a brick wall and then be multi-textured
with a light-map to give the illusion of being lit.
Natural
light
Light that exists in nature, such as sunlight or moonlight, depends on
the time of day, season and location on the Earth. The sunlight a clear
day have an RGB value of about R:250 G:255 B:175. For simulating overcast
it might be a good idea to add the blue component, whereas a sunset could
be a little more orange. As opposed to artificial light, the natural light
has only one source (the sun) and can most effectively be recreated using
a distant light.
Node
The basic graph element used to represent distinct items (vertices, faces,
etc.). A signal coordinate in a grid, or finite element grid point used
to describe the structure. A node will lie on each vertex of a finite
element, and additional nodes may lie along element edges to define curved
element topology.
Non-planar
Non-planar refers generally to a polygon where all points do not
reside in the same plane and can occur only with polygons using more than
three points. Non-planar polygons can cause erratic rendering errors.
As an example, a square piece of cardboard sitting upon a tabletop will
become non-planar on all vertices when lifted by a corner. Inherent in
manipulation and deformation of a model, non-planar "holes"
can appear in the surface consistency of models. Solutions include "tripling"
(actually halving the quads diagonally) or tessellating the polygons into
triangles. As an example, a triangular piece of cardboard sitting upon
a tabletop will remain planar on one vertex when lifted by any corner.
Thus, when joined on their vertices, a group of triangles are more robust
when deformed.
Normal
A normal is a vector that is perpendicular to a mathematical entity, such
as a line or a plane. In 3D, the normal can be used to define the direction
a polygon is facing, and is used extensively for backface culling and
light computation. What is normal??
NTSC
(National Television Standard Committee). The most common video standard
in the United States and Japan. It has a frame-rate of 30 fps. 60 times
per second every other scan line is changed, resulting in smoother transitions.
Its pixel resolution is 720x486 with a pixel aspect of .9
Null
Non-renderable help-object used in modeling programs to simplify the manipulation
of 3D-objects and texture mapping.
NURBS
Abbreviation for Non-Uniform Rational B-Splines.
Nurnies
American slang. See greeblies.
Object
A model or construction that when placed in a scene will render to represent
a thing it represents from the real world.
Object
Oriented Graphics
Different from bitmap format, this image type consists of objects that
have definite mathematical formulas behind them. These images always print
at the maximum quality specified by the printer, unlike bitmapped images
that always print at the same quality level. They can also be referred
to as “vector graphics”
Omni-directional
light
Same as a point light.
Opacity
The opposite of transparency.
Opacity
map (or transparency map)
Makes the surface more or less transparent depending on the pixel
intensity (color value) of the opacity map where normally black is transparent
and white is opaque.
OpenGL
A 3D graphics API that includes capabilities for 2D imaging. Basically,
OpenGL is a set of instructions that can be used by a program to interpret
images and display them on the screen. LightWave uses OpenGL for all its
displays.
Optical
light effect
If the observer (or camera) looks directly at a bright lightsource it may
appear to glow. If the light is refracted through a lens or even your
own eyelashes (try squinting towards a spotlight!), the light will appear
to form star-like patterns.
Orbit
To travel around a target - more commonly circular, but a comet's orbit
can be elliptical.
Origin
The world Origin is the absolute center of the LightWave universe. A local
Origin is the center of an object. Both are defined by the XYZ coordinates
of 0, 0, 0.
Orthogonal
A view that displays a parallel projection along one of the major axes.
In an orthogonal view, the camera is oriented so it is perpendicular (orthogonal)
to specific planes: the Top view faces the XZ plane, the Front view faces
the XY plane, and the Right view faces the YZ plane. An orthogonal view
eliminates the effect of distance from a viewpoint, which provides a useful
means of locating points and objects in 3D space and is particularly helpful
when modeling objects in wireframe mode. An orthogonal view is in contrast
to a perspective view.
Orthogonal
direction
There six different orthogonal directions in a three-dimensional space:
up, down, back, forward, left and right
Orthographic
projection
Viewing system where the projectors are parallel and therefore doesn't
create a perspective with foreshortening.
PAL
(Phase Alternating Line). The most common video standard in Europe. It
has a framerate of 25 fps. It is interlaced, which means that 50 times
per second every other scan line is changed, resulting in smoother transitions.
The resolution is 720x576 pixels and the pixel aspect ratio is 1.0667.
Pan
To rotate the camera horizontally. As opposed to the orbit movement, the
pan rotates the camera around a single axis, as if it where mounted on
a tripod.
Panel
In a 3D program, a screen that serves many functions such as informing
the user of errors, asking for user input, or informing the user of the
state a program is currently in. Otherwise known as a window or requester.
Parabola
A plane curve formed by the intersection of a right circular cone and a
plane parallel to an element of the cone or by the locus of points equidistant
from a fixed line and a fixed point not on the line.
Parameterization
Technique for assigning values to the edit points as they are spaced along
the length of a curve. Can be either uniform parameterization or non-uniform
parameterization (chord length). The first edit point on the curve had
the value 0.0 (regardless of whether it is uniform or non-uniform) and
the following edit points are assigned greater values the closer they
lie to the other end.
Parameters
Also known generally as properties, parameters are the "atomic"
elements of a property set whose values determine the behavior of something.
A parameter is one degree of freedom. You can set parameters in property
editors.
Parent
An object that influences the motion of another object in a hierarchy,
called the “child”.
Parenting
The process of creating a hierarchical organization of objects in a scene.
In parenting, an object (called the parent object) is "parented"
to another object (called the child object). Parenting relationships can
be nested to any degree, so that one or more objects are the children
of another object, which is in turn the child of another.
Particles
2-dimensional objects typically used in large quantities to create effects
like rain and explosions.
Passive
Polarized 3D glasses
3D glasses made with polarizing filters. Used in conjunction with a view
screen that preserves polarized light.
Penumbra
A partial shadow, as in an eclipse, between regions of complete shadow
and complete illumination, a fringe region of partial shadow around an
umbra.
Perspective
A traditional art method of creating the illusion of three-dimensional
form and distance on a two-dimensional surface. Perspective provides a
three-dimensional view of the scene that indicates depth. In a perspective
view, objects appear to converge toward a central vanishing point, and
objects closer to the camera appear larger than those farther away. A
perspective view is in contrast to an orthogonal view.
Perspective
projection
Simulating three-dimensionality by using foreshortening that triggers the
human perception to interpret a two-dimensional image as if it was three-dimensional.
An object is drawn smaller and smaller the further it is from the observer.
This is achieved by using a center of projection to which all projectors
converge, as opposed to where the projectors are parallel.
Philip
Nelson
Lord of the Dance.
Phong
Shading
The most frequently used interpolative shading technique used today. It
uses a linear combination of three components - the ambient component,
the diffuse component and the specular component. The placement of the
highlight is less dependant on the underlying polygons as Gouraud shading
since Phong shading interpolates the normals on a per-pixel basis instead
of interpolating the light intensity based on the distance to the three
vertices.
Photorealism
The process of generating computer images that mimic photographs.
Pitch
The amount that the camera or an object in the scene is tilted up or down.
If you nod your head yes, you are rotating your head in the pitch axis.
Pivot
Point
A single point, usually in the geo-center of an object that is used for
many functions. It is the point that is addressed to locate an object’s
position in 3D space. It is also the point around which all rotational
moves are made and is the reference point for transformations and scaling.
Pixel
Short for PIcture ELement, a pixel is the smallest element of computer
or video display.
Plane
Plane refers to a two-dimensional (i.e., flat and level) surface. Imagine
a plane as a piece of glass that is infinitely large, but has no depth.
Plug-in
A plug-in is a program that works with and extends the functionality of
LightWave.
Point
A fundamental building element of an object in 3D space with an XYZ location.
Point coordinates are the minimum information from which the geometry
of an object can be calculated.
Point
light
Light source emitting light in all directions (omni-directionally) from
a single point in space. It takes six shadow (one in each orthogonal direction)
calculations to render shadows generated by a point light, which means
that inserting multiple point lights in a scene might slow down rendering
time considerably. Point light emanates in all directions, think "light
bulb".
Polygon
Geometric shape in one or many planes. Polygonal modeling consists of using
many faces to create the shape. Since polygons in most cases are faceted
simplifications of a much smoother shape, they are more or inaccurate,
as opposed to the more organic NURBS. The more the tessellation, the higher
and the closer the accuracy compared to the desired shape.
Poly-Line
A geometric entity composed of one or more connected segments that are
treated as single entity.
POV
Abbreviation for Point of View.
Primary
colors
There are three primary colors of light: red, green and blue (RGB). Light
colors are additive, which means that if these three colors are combined
equally, the result is a white light. Black is thus absence of light.
Primitive
Basic geometric shape used in modeling. Some primitives consist of a combination
of different primitives. Cone, box, sphere, tube, torus, and disc are
common primitives.
Procedural
map
A map (often three-dimensional) generated mathematically instead of using
an image. The procedural map does not need texture coordinates. A map
that is not based on an image but generates the map using a set of user-customized
variables.
Procedural
Textures
Mathematically generated textures (2D and 3D). Their advantage is that
they are largely independent of the projection type.
Projected
shadow
A shadow that falls from an object and projects on a surface.
Projection
Map
A mapping procedure that allows the user to apply the map to multiple objects
as if they were one.
Quad
A polygon with four sides, short for quadrilateral.
Quantize
This tool causes points to snap to a specific (X, Y, Z) coordinate. This
tool is generally used when a lot of precision is required.
Quaternion
Magically delivered full-grown to W. R. Hamilton in 1843, quaternions are
mathematical objects consisting of a scalar and a vector which together
form a four-dimensional vector space. Although having interesting uses
in mathematics, their main use in computer graphics resides in their capability
of easily representing 3D rotations. Although impossible to visualize,
they suffer from no singularities like Euler angles, and are also easy
to smoothly interpolate for keyframe animation (using a mathematical operation
called SLERP for Spherical LinEar intERPolation
Radiosity
A more physically correct approach (developed in 1984 by Siegel and Howell)
to simulate propagation of light in a virtual environment. It takes into
account the fact that light bounces off a surface and creates diffused
lighting on the surrounding objects. The scene is divided into a certain
amount of triangles that are used to represent the original scene (which
speeds up the time-consuming process), and then radiation interaction
is calculated using these triangles. As far as visual quality is concerned,
the more crucial the part of the scene the denser the triangles must be.
This technique creates much more realistically lit environments, however
it takes much longer to render due to the massive amount of calculations.
Rail
Clone
This tool creates multiple copies of an object that are evenly spaced along
one or more user-defined curves.
Rail
Extrude
This tool is used to extrude polygons along a specified line or combination
of lines. This allows the user to create a shape other than that created
from a normal, static extrude.
Rapid
Prototyping
The process by which a computer model of a 3D object is turned into a real
object. Rapid prototyping methods vary but often involve laying down strata
of base material which is then bonded together using a substance like
cyanoacrylate (superglue).
Rasterization
The process of, on a per pixel basis, determining what value to assign
to the pixels on the screen from a vector based image.
Ray-traced
shadow
Shadow created by tracing the light rays from a light source. The ray-traced
shadows are more accurate than those created by shadow map, but takes
longer time to render and always have crisp edges
Ray
tracing
An advanced rendering technique capable of calculating reflections, refractions
and shadows.
Raytraced renderings
take more time to generate, but have a photorealistic quality. To keep
rendering time to the minimum, keep the to the smallest value necessary.
Ray
tracing depth (ray recursion limit)
Number of times the light bounces off a surface when ray tracing. Used
to create reflections and/or refractions. For example, ray tracing two
mirrors facing each other with the ray tracing depth set to 3 will allow
the image of the reflected mirror to show the first mirror in it.
Reflection
Light that bounces off a surface. A mirror is highly reflective, whereas
the reflection of a matte rubber surface is insignificant.
Reflection
map
Simulates reflections in a surface using the reflection map instead of
actually ray tracing the reflected image. This speeds up rendering time,
but can also be a give-away if the scene is animated.
Reflection-illumination
model
Model used when creating two-dimensional images from three-dimensional
meshes. To produce more realistic and convincing images, the reflection
model imitates attributes of real-life objects.
Refraction
When light passes through a transparent material and into a denser or less
dense medium the light rays are refracted and change direction. Each material
has its own and depending on de density of the material the refraction
is more or less evident. Refractions are calculated similarly to reflections
using ray tracing.
Refraction
index
A value describing the amount of refraction that takes place in a specific
transparent material. For vacuum the refraction index is 1.0000, for air
1.0003, for glass approximately 1.5 and for water 1.3333.
Refraction
map
An image to control the level of refraction across a surface where
dark values indicate a low refractive index and bright ones a high refractive
index.
Render
To cause to become, to make, to process. To mathematically generate geometries,
algorithms, reflections, etc. Our work would be meaningless without the
ability to render. Creating a final image of a model that shows all of
the surface properties that have been applied to an object. This process
involves adding all colors; bump maps; shading; and other elements that
add realism. In a normal 3D program, the user can view the wireframe of
the created image. When an image is rendered, the wireframe is covered
with the specified colors and properties.
Render
pass
A division of a scene according to different aspects (such as highlight,
mattes, or shadows) for the purposes of applying specific rendering options.
Passes can then be composited during post-production. The default pass
is the beauty pass, which includes all objects in the scene. Preset passes
include matte, shadow, and highlight passes. You can also define your
own passes to include any object you want to be affected by specific rendering
properties. Render passes are further divided into partitions.
Rendering
pipeline
Description given to the process of creating the rendered images. Some
studios have a process by which all the images go through. Some render
in passes, one for the base, then the shadows, then the reflections, etc.
This process is the pipeline.
Resolution
The number of picture elements in an image.
Revolution
A modeling term defining a surface made by rotating a curve around the
axis of another curve.
RGB
color model
A color model that mixes the three primary colors to produce colors. To
create yellow, red and green are mixed without any blue component. The
higher the value of the red, green and blue, the clearer the color. Lower
RGB values give darker colors, higher gives lighter.
Rigging
The process of making an object ready for animation. This does not have
to be just characters; it is the same for all objects. Rigging involves
creation and implementation of bones, hierarchies, clamps, weight maps
and sliders.
Right-handed
coordinate system
A coordinate system (frequently used in 3D-graphics applications) whose
positive Z-axis emerges from the screen towards the user, just like the
one used in mathematics, as opposed to the left-handed coordinate system.
ROFL
Rolling on the floor, laughing.
ROFLMAO
Rolling on the floor, laughing my ass off.
Roll
The amount that a camera is tilted to the left or right. Also known as
the bank angle.
Rotoscoping
A technique in which video or film images are placed in the background
of a scene, one frame at a time. You can use these reference images to
create your own animation by tracing objects from the images or matching
your objects with the images' motion. You can zoom and pan the scene while
maintaining perfect registration with the imported background.
Row
Interleaved
A format to create 3D video or images in which each row or line of video
alternates between the left eye and the right eye (from top to bottom).
RTFM
Read the Freaking manual (cleaned up for you kiddies!)
Rule-based
design
The definition of relationships between objects in the design. Another
name used to describe knowledge-based design.
Scalar
A quantity, such as mass, length, or speed, that is completely specified
by its magnitude and has no direction, a one dimensional value.
Scanner
Device for reading images (from books, photos etc.) into the computer.
This is useful for creating realistic textures. With a 3D scanner it is
even possible to capture three-dimensional objects and convert them into
models. A person whose mother took part in a project created by Dr. Paul
Routh and was given ephemerol injections. Some can control minds and cause
heads to expolode.
Scrub
The process of manually dragging the frame advance control slider on the
timeline to see or hear its effect on video/audio.
S-Drill
Refers to Solid Drill. Acts just as a drill would, using a 3D object as
the drill bit. This tool can be used to take sections out of objects or
perform other functions that a drill might.
Seamless
A seamless texture can be tiled without visible transitions where the bitmap
begins and ends. This means that the upper part of the bitmap can be placed
next to the lower part of the bitmap (the same goes for the left/right
part) forming a pattern that is apparently coherent. Seamless textures
have no apparent seams.
SECAM
Séquential Couleur à Memoire. The television broadcast standard for France,
the former USSR, and various eastern European countries. Like PAL, SECAM
is based on a 50 Hz power system, but it uses a different encoding process
and displays 819 lines interlaced at 50 fields per second. SECAM is not
compatible with NTSC or PAL, but conversion between the standards is possible.
Secondary
animation
Once the main movements of animation have been applied, this refers
to the detail animation step. Hoses bouncing with a robot walking, flab
wiggling with a heavyset character, these refer to secondary animation.
Sector
Convex volume used to speed up rendering time.
Self-shadow
Apparent shadow due to lack of incoming light
Self-illumination
(or luminosity)
Allows non-homogene self-illumination of the surface. Some parts can be
self-illuminated, some partially self-illuminated, and some not at all)
based on the pixel intensity of the self-illumination map.(normally black=left
unchanged white=self-illuminated
Session
A session is a single use of an application. A session begins when you
first start the application and ends when you exit.
Shaded
mode
Shaded mode generally refers to a viewport that has its Rendering Style
(Display Options panel or viewport title bar) set to something other than
wireframe. These modes show polygon surfaces with some level of shading.
Shading
Simulating that an object is lit by a light source.
Shadow
An area that is not or is only partially lit because of the interception
of light by an opaque object between the area and the source of radiation.
Shadow
map
Bitmap generated by the rendering engine during a pre-render pass of the
lit scene. Generally a shadow map is less precise than a raytraced shadow,
but takes less time to render. As opposed to a ray-traced shadow, a shadow
map can create shadows with smooth edges. Furthermore, the shadow map
is unable to show the color cast by a transparent object. The quality
of the shadows in the rendered image depends on the size of the shadow
map. The bigger the map the nicer the shadows. Too small shadow map might
result in aliased or stairstepped edges. For example, a 256x256 shadow
map (65k)is normally sufficient for resolutions of 320x200 and less. If
an object is far away from the light source, the shadow map will have
to be increased in order to maintain visual quality. If the final rendering
is in high-resolution, the shadow map also needs to be hi-res.
Skew
Modifying an object by tilting it
Smoothing
Technique that, when rendering or shading, smoothes out the edges between
segments making objects appear smoother than their geometry really are.
Soft
shadow
A shadow that does not have hard edges.
Space
A set of elements or points satisfying specified geometric postulates:
non-Euclidean space. The infinite extension of the three-dimensional region
in which all matter exists.
Specular
This property determines how shiny (and sometimes wet) an object appears.
It represents the highlight that the light creates when shining on an
object.
Specular
component
Part of the reflection-illumination model. Specular surfaces are capable
of reflecting light like a mirror.
Specular
map
Replaces the specular component of the reflection-illumination model, thus
only visible in an object's surface's highlights.
Specular
reflection
The brightest area on a surface, reflecting surrounding light sources,
creating highlights.
Spherical
Image Map
One of the many methods of applying a texture to a surface. This
method applies the texture to an object as it would apply the texture
to a sphere. There are many other methods of texturing objects, such as
Cubic and Planar image mapping.
Spinning
light trick
Trick to create soft shadows with ray tracing. It involves parenting multiple
lights to a null and spinning the null.
Spline
(Curves)
LightWave uses splines or curved paths between keys while moving items
about. When modeling, splines refer to open or closed curves.
Spline
Cage
A spline cage is usually a three-dimensional object made up of connected
spline curves.
Spline
Patching
Spline patching is the process of adding polygons to fill in areas
outlined by splines.
Spot
A small opaque circle placed in front of a light, usually to remove the
a specular hot spot off of an object.
Spotlight
A lightsource emanating light in one direction only, in the shape of a
cone.
Staircasing
(or stairstepping)
A graphical flaw caused by insufficient resolution. When rendering an object
its contours might stand out too crisply from the background and the pixels
might be obviously "zig-zagged", or look like stairs. To prevent
this, pixels can be blended into their neighbors' colors by anti-aliasing.
Stencil
When using the drill tool, the stencil option adds the details of
the drilling polygon to the polygon being drilled. This creates new geometry
on a shape.
Stereoscopic
3D
Two separate photographs taken from slightly different angles that,
when compiled, appear three-dimensional.
Stretch
Tool
Allows the user to change the dimensioning of an object along a particular
axis. Basically, it stretches stuff.
Subdivide
This tool divides any selected polygons with three or four sides into smaller
polygons. This makes an object appear smoother, but also makes the model
more complex.
Subdivision
Surfaces
Subdivision surfaces are a technique to create a smooth curved surface
from a coarse polygon mesh. Several different subdivision schemes have
been developed since Catmull & Clark first introduced the idea back
in 1978. The most well known schemes are the triangle based Loop scheme
and Catmull & Clark's original scheme, which is based on quad polygons.
Subdivision surfaces moved out to the public in Pixar’s movies, Toy Story
2 and Geri’s Game.
SubPatch
Refers to a modeling mode wherein polygons become a cage that controls
an underlying mesh of subdivision surfaces.
Subtractive
opacity
Sort of opacity that subtract the background color from the material's
color of the transparent object
Super
pixel
They are created in a supersampling image. Groups of the superpixels are
filtered into the one single pixel that is displayed on the output display.
Supersampling
Generating images at a resolution n times n larger than the display
resolution and then filtering the co-called superpixels into the smaller
resolution image, creating smooth images with anti-aliasing.
Surface
The outer part of an object. The surface attributes can be changed using
the Surface panel. Such attributes as name, color, and many other features
affect the appearance of an object.
Taper
Modifying an object by progressively narrowing it along an axis.
Target
In aiming the camera, the target is the object that is selected for the
camera to point toward. The target is in the center of the scene.
TD
Short for Technical Director. Although some TDs don’t wear shorts.
Technical
Director
A job in a studio that concerns mainly making rigs. Also to help out the
other departments where ever possible. They are the problem solvers.
Tessellation
Increasing the detail level of a polygonal 3D model by increasing its number
of polygons, usually triangles . The more triangles, the smoother the
shape and subsequently the larger the model. The tessellation can be performed
by dividing one triangle into two (or more) smaller ones. By doing this
the new, more faceted model can be modified without losing too much of
its smoothness.
Texture
Normally texture describes the attributes of a surface, for example if
it’s coarse, smooth, wrinkled or rough, but it also used with the meaning
of texture map. There are textures made up from bitmaps (texture map)
and textures generated mathematically (procedural map). The specification
of how the surface of an object will look. Textures can be anything from
simple, solid colors to complex images representing the surface of the
object. The simplest example of a texture is placing a picture on a flat
plane. The picture is the texture being applied to the plane.
Texture
coordinates
Coordinates used to describe how to map a texturemap onto an object. There
are different kinds of techniques to apply the texture: planar, box, cylindrical,
spherical and shrink map. Their names indicate how the texture is projected
onto the object the mapping coordinates are applied to. The shrink map
projection differs from the spherical projection in the way it only has
one pole where all seams meets. The modeler can manipulate the texture
coordinates to or mirror the texture. The procedural maps do not need
texture coordinates.
Texture
map
Map wrapped over the surface of an object. The texture map needs to be
spaced correctly in U and V direction over the object.
Texture
Mapping
The process of projecting a (usually) two-dimensional image onto a three-dimensional
face such as a triangle or a quad, texture mapping is a relatively cheap
way of adding tremendous detail to a scene without resorting to extremely
detailed meshes that take an inordinate amount of memory and time to render.
Tiling
Repeatedly placing the same texture next to itself on the same surface,
creating a pattern from one image. This is achieved by increasing the
texture coordinates on a polygon to a value greater than 1. Normally,
the entire bitmap is tiled from 0.0 to 1.0 in u- (=x) and v (=y). Tiling
textures means placing them next to one and other.
Timeline
The slider under the Layout viewport representing time in animation.
Transformation
The act or an instance of transforming. The state of being transformed.
A marked change, as in appearance or character, usually, HOPEFULLY for
the better.
Truck
To move the camera in the viewing plane.
Tween
Tweening is the internal process of calculating the animation channel
values of all frames between keys.
Twist
Twisting a mesh by rotating its vertices non-uniformly along an axis.
U-direction
Represents a grid line in one direction (normally that of the original
curve) of a UV texture map.
Umbra
A dark area, especially the blackest part of a shadow from which all light
is cut off. The completely dark portion of the shadow cast by the earth,
moon, or other body during an eclipse.
Unify
This command creates single-sided polygons according to the properties
of their surface normals. Basically, this tool transforms polygons that
share points into a single polygon.
Union
One of the options in the Boolean tool. This option makes an object
that is a combination of the two objects. A combination so formed, especially
an alliance or confederation of people, parties, or political entities
for mutual interest or benefit.
UV-grid
A grid system for identifying points on a surface. The U-direction and
V-direction are for the surface, what the X-axis and Y-axis are for the
coordinate system.
V
(Vertex) Maps
V Maps is an abbreviation for vertex maps. V Maps provide additional information
associated with object points (vertices), like weight, UV and morph maps.
V-direction
Represents a grid line in one direction (normally "up/down")
on the surface of an object.
Vector
Entity with both magnitude and direction. A three-dimensional vector is
written as:
V=(v1, v2, v3) where each component is a scalar.
Vertex
(pl. vertices) three-dimensional point that is the smallest component in
a 3D-mesh.
Vertex
count
The number of vertices in a scene. Remember, the higher the mesh complexity
the longer the rendering time.
Vertex
normal
Even though it is a single point in three dimensional space, its normal
can be calculated based on the normal of the face they are describing.
The three vertex normals of a single triangle without any neighboring
triangles are set to be the same as the polygon's normal. For triangles
surrounded by other triangles, the vertex normals are the average of the
surrounding face normals.
View
frustum
Representing the field of view of the camera, the view frustum is a pyramid
volume with the top sheared off. The top of the pyramid represents the
viewport of the camera (usually the screen), and is often called the near
(or hither) plane, while the bottom is called the far (or yon) plane.
View
frustum culling
Removing faces that lie outside the observer's view. Only the faces that
is within the view frustum is kept for rendering - speeding up rendering
time and helping to maintain a high framerate.
Viewport
Window area displaying orthogonal or perspective projection in a 3D application.
The screen can either contain one big viewport or several smaller, tiled
viewports. By simultaneously using several viewports displaying a three-dimensional
object from different sides (e.g. top, front, left, perspective), modeling
in a virtual 3D environment is made possible.
VIPER
Versatile Interactive Preview Render window that provides the user with
an interactive previewing system.
Volume
When selecting, a volume of an object is a 3D representation of the area
to be edited. When editing, all of the parts of objects contained within
this 3D selection can be edited without changing what lies outside of
the selection.
Volumetric
fog
Fog that, opposed to ordinary fog, is restricted to fit within a
containing volume.
Volumetric
light
Light simulating illumination of particles floating in mid-air, thereby
making the light cone itself visible.
Vortex
A tool that rotates an object more in the center than in the outer
edge. This tool can be easily related to a tornado, where the wind in
the center moves faster than the wind in the outer part of the cone.
Voxel
Short for VOlume ELement, this term refers to a specific rendering technique
common in medical visualization as well as some interactive media. In
essence, a voxel is a three-dimensional pixel, that is, a cube, with a
specific color.
Weld
This command takes the selected points and combines them into one point,
a single point that is specified by the last point that is selected.
WIP
Short for Work In Progress.
Wireframe
A way of visualizing geometry by drawing lines between its vertices and
not shading the surfaces within.
World
coordinate system
The coordinate system, normally in three dimensions, used to describe the
location in space of a specific point called vertex.
X-Axis
Usually is the axis that is left and right.
Yaw
To turn about the vertical axis, also known as heading.
Y-Axis
Usually is the axis that is up and down.
Y-up
Coordinate system with the Y-axis pointing upwards.
Z-Axis
Usually is the axis that is in and out.
Z-buffer
Also called depth buffer, the z-buffer is a two-dimensional matrix
of 16- or 32-bit integers with the same dimensions as the screen (or viewport).
Whenever a polygon is drawn to the screen, the rasterizer checks the corresponding
z-buffer value for each screen coordinate and skips drawing the current
pixel if the z value is marked as being closer. This allows for some nice
effects such as overlapping 3D models, and completely solves the rendering-order
problem.
However, this
comes at the price of slower performance and greater memory usage, two
factors that have become more or less moot with the proliferation of modern
3D accelerators that tend to support z-buffers in hardware.
Z-up
Coordinate system with the Z-axis pointing upwards. |