Glossary


2DTwo-dimensional. See also planar.

3DThree-dimensional. See also spatial.

3DMFSee QuickDraw3D Object Metafile.

3D pointing deviceAny physical device capable of controlling movements or specifying positions in three-dimensional space.

3D ViewerA shared library that you can use to display 3D objects and other data
in a window and to allow users limited interaction with those objects. See also viewer object.

acceleratorSee graphics accelerator.

adjointThe transpose of a matrix in which each element has been replaced by
its cofactor.

adjoint matrixSee adjoint.

affine matrixA matrix that specifies an affine transform.

affine transformAny arbitrary concatenation of scale, translate, and rotate transforms. An affine transform preserves parallel lines in the objects transformed.

aliasingThe jagged edges (or staircasing) that result from drawing an image on a raster device such as a computer screen. Compare antialiasing.

alpha channelA color component in some color spaces whose value represents the opacity of the color defined in the other components. Compare ARGB color structure.

ambient coefficientA measure of an object's level of reflection of ambient light.

ambient lightAn amount of light of a specific color that is added to the illumination of all surfaces in a model.

ambient reflection coefficientSee ambient coefficient.

antialiasingThe smoothing of jagged edges on a displayed shape by modifying the transparencies of individual pixels along the shape's edge. Compare aliasing.

APISee application programming interface.

application coordinate systemSee world coordinate system.

application spaceSee world coordinate system.

application programming interface (API)The total set of constants, data structures, routines, and other programming elements that allow developers to use some part of the system software.

areaA rectangular section of a plane. Defined by the TQ3Area data type.

ARGB color spaceA color space whose components measure the intensity of red, green, and blue, together with the opacity (or alpha component) of the color thus defined.

ARGB color structureA data structure that contains information about a color and its opacity. Defined by the TQ3ColorARGB data type.

artifactAny oddity or unwanted feature of a rendered image. Compare aliasing.

aspect ratioThe ratio of the width of an image or other rectangular area to its height.

aspect ratio cameraA type of perspective camera defined in terms of a viewing angle and a horizontal-to-vertical aspect ratio.

aspect ratio camera data structureA data structure that contains basic information about an aspect ratio camera. Defined
by the TQ3ViewAngleAspectCameraData data type.

attenuationThe loss of light intensity over distance.

attributeSee attribute object.

attribute metahandlerA metahandler that defines methods for handling custom attribute data.

attribute objectA type of QuickDraw3D object that determines some of the characteristics of a model, such as the color of objects or parts of objects in the model, the transparency of objects, and so forth. An attribute is of type TQ3Element. See also ambient coefficient, diffuse color, highlight state, normal vector, shading parameterization, specular color, specular reflection exponent, standard surface parameterization, surface shader, surface tangent, transparency color.

attribute setA collection of zero or
more different attribute types and their associated data.

axisSee coordinate axis.

back clipping planeSee yon plane.

backface cullingIgnoring backfacing polygons during rendering. Backface culling can reduce the amount of time required to render a model. Compare hidden surface removal.

backfacing polygonAny polygon in a surface whose surface normal points away from a view's camera.

backfacing styleA type of QuickDraw3D object that determines whether or not a renderer draws shapes that face away from a scene's camera.

badgeA visual element in a frame of a 3D model displayed by the 3D Viewer that distinguishes the frame from a static image.

base classSee parent class.

big-endianData formatting in which each field is addressed by referring to its most significant byte. See also little-endian.

binary fileA file object whose data is a stream of raw binary data, the type of which is indicated by object type codes. Compare text file.

bitmapA two-dimensional array of values, each of which represents the state of one pixel. Defined by the TQ3Bitmap data type. See also pixmap, storage pixmap.

bounding boxA rectangular box, aligned with the coordinate axes, that completely encloses an object. Defined by the TQ3BoundingBox data type.

bounding loopA section of code in which all bounding box or sphere calculation takes place. A bounding loop begins with a call to the Q3View_StartBoundingBox (or Q3View_StartBoundingSphere) routine and should end when a call to Q3View_EndBoundingBox (or Q3View_EndBoundingSphere) returns
some value other than kQ3ViewStatusRetraverse. A bounding loop is a type of submitting loop. See also picking loop, rendering loop, writing loop.

bounding sphereA sphere that completely encloses an object. Defined by the TQ3BoundingSphere data type.

bounding volumeA bounding box or a bounding sphere.

boundsSee bounding volume.

boxA three-dimensional object defined by an origin (that is, a corner of the box) and three vectors that define the edges of the box meeting in that corner. Defined by the TQ3BoxData data type.

B-spline curveA curve that passes smoothly through a series of control points.

B-spline polynomialA parametric equation that defines a B-spline curve.

B-spline surfaceA surface that passes smoothly through a series of control points.

cameraSee camera object.

camera angle buttonA button in the controller strip of a viewer object that, when held down, causes a pop-up menu to appear listing the available cameras. Compare distance button, move button, rotate button, zoom button.

camera coordinate systemThe coordinate system defined by a view's camera. Also called the view coordinate system. Compare local coordinate system, window coordinate system, world coordinate system.

camera data structureA data structure that contains basic information about a camera. Defined by the TQ3CameraData data type.

camera locationThe position, in the world coordinate system, of a camera. Also called the eye point. Compare camera placement structure.

camera objectA type of QuickDraw3D object that you can use to define a point of view, a range of visible objects, and a method of projection for generating a two-dimensional image of those objects from a three-dimensional model. A camera object is an instance of the TQ3CameraObject class. See also aspect ratio camera, orthographic camera, view plane camera.

camera placementThe location, orientation, and direction of a camera. See also camera placement structure.

camera placement structureA data structure that contains information about the placement (that is, the location, orientation, and direction) of a camera. Defined by the TQ3CameraPlacement
data type.

camera rangeThe spatial extent that lies between the hither and yon planes of a camera. See also camera range structure.

camera range structureA data structure that contains information about the hither and yon clipping planes for a camera. Defined by the TQ3CameraRange data type.

camera spaceSee camera coordinate system.

camera vectorSee viewing direction.

camera view portThe rectangular portion of a view plane that is to be mapped onto the area specified by the current draw context.

camera view port structureA data structure that contains information about the view port of a camera. Defined by the TQ3CameraViewPort data type.

capA plane figure having the shape of an oval that closes the base of a cone or one end of a cylinder.

Cartesian coordinate systemA system of assigning planar positions to objects in terms of their distances from two mutually perpendicular lines (the x and y coordinate axes), or of assigning spatial positions to objects in terms of their distances from three mutually perpendicular lines (the x, y, and z coordinate axes). Compare polar coordinate system, spherical coordinate system.

center of projectionThe point at which the projectors in a perspective projection intersect.

child classA class that is immediately below some other class (the parent class) in the QuickDraw3D class hierarchy. For example, the light class is a child class of the shape class. A child class inherits all of the methods of its parent. Also called a subclass.

clampFor a shader effect, to replicate the boundaries of the effect across the portion of the mapped area that lies outside the valid range 0.0 to 1.0. Compare wrap.

classSee QuickDraw3D class.

class typeSee object type.

clipping planeEither of the two planes that limit the part of a model that is rendered. See also hither plane, yon plane.

closedNot open. Compare open.

color spaceA specification of a particular method for representing colors. Compare RGB color space.

complementThe set of points that lie outside a given solid object. The complement of the object A is represented by the function ÂA. Compare intersection, union.

componentSee mesh component.

concave polygonA polygon with at least one interior angle greater than 180°. Compare convex polygon.

conicSee conic section.

conic sectionAny two-dimensional curve that is formed by the intersection of a plane with a right circular cone. The most common conic sections are ellipses, circles, parabolas, and hyperbolas. Compare nonuniform rational B-spline (NURB).

connectedSaid of a pair of mesh vertices if an unbroken path of edges exists linking one vertex to the other. Compare mesh component.

constant shadingA method of shading surfaces in which the incident light color and intensity are calculated for a single point on a polygon and then applied to the entire polygon. Compare Gouraud shading, Phong shading.

constant subdivisionA method of subdividing smooth curves and surfaces. In this method, the renderer subdivides a curve into some given number of polyline segments and a surface into a certain-sized mesh of polygons. Compare screen-space subdivision, world-space subdivision.

constructive solid geometry (CSG)A way of modeling solid objects constructed from the union, intersection, or difference of other solid objects.

container faceThe face in a mesh that contains a particular contour.

contourA list of vertices. In a mesh, a contour specifies a hole in a face. Compare container face.

controllerSee controller object.

controller channelAny piece of information sent from an application to an input device. Compare controller value.

controller data structureA data structure that contains information about a controller. Defined by the TQ3ControllerData
data type.

controller objectA QuickDraw3D object that represents a 3D pointing device. A controller object is an instance of the TQ3ControllerObject class. See also tracker object.

controller stateSee controller state object.

controller state objectA QuickDraw3D object that represents the current channels and other settings of a controller. A controller state object is an instance of the TQ3ControllerStateObject class.

controller stripA rectangular area at the bottom of a viewer object that contains one or more controls (usually buttons). Compare camera angle button, distance button, move button, rotate button, zoom button.

controller valueAny piece of information sent from an input device to an application. Compare controller channel.

control pointA geometric point used to control the curvature of a curve or surface. Compare knot.

convex polygonA polygon whose interior angles are all less than or equal
to 180°. Compare concave polygon.

coordinate axisA line in a plane or in space that helps to define the position of geometric objects. See also x axis, y axis,
z axis.

coordinates(1) See coordinate system. (2) See tracker coordinates.

coordinate spaceSee coordinate system.

coordinate systemAny system of assigning planar or spatial positions to objects. Compare Cartesian coordinate system, polar coordinate system, spherical coordinate system.

cornerSee mesh corner.

cross productThe vector that is perpendicular to two given vectors and whose magnitude is the product of the magnitudes of those two vectors multiplied by the sine of the angle between them. The cross product of the vectors u and v is denoted u v. Compare dot product.

CSGSee constructive solid geometry.

CSG equationA value that encodes which CSG operations are to be performed on a model's CSG objects.

CSG object IDA number, attached to an object as an attribute, that identifies an object for CSG operations.

C standard I/O librarySee standard I/O library.

C string objectA QuickDraw3D object that contains a standard C string (that is,
an array of characters terminated by the null character).

cullingSee backface culling.

customSupplied by your application, not by QuickDraw3D.

custom surface parameterizationA parameterization of a surface supplied by your application. Compare natural surface parameterization, standard surface parameterization.

database fileA metafile in which all shared objects contained in the file are listed in the file's table of contents. See also normal file, stream file.

database modeThe mode in which a database file is opened. See also normal mode, stream mode.

default surface parameterizationSee standard surface parameterization.

degrees of freedom (DOF)The number of dimensions that are independently specifiable by a particular input device. For example, a slider or a dial has one degree of freedom; a mouse typically has two degrees of freedom.

device coordinate systemSee window coordinate system.

device spaceSee window coordinate system.

differential scalingA scale transform in which the scaling values dx, dy, and dz are not all identical. Compare uniform scaling.

diffuse coefficientA measure of an object's level of diffuse reflection.

diffuse colorThe color of the light of a diffuse reflection.

diffuse reflectionThe type of reflection that is characteristic of light reflected from
a dull, nonshiny surface. Also called Lambertian reflection. Compare specular reflection.

diffuse reflection coefficientSee diffuse coefficient.

directional lightA light source that emits parallel rays of light in a specific direction.

directional light data structureA data structure that contains information about a directional light. Defined by the TQ3DirectionalLightData data type.

dirty stateA Boolean value that indicates whether an unknown object is preserved in its original state (kQ3False) or should be updated when written back to the file object from which it was originally read (kQ3True).

display groupA type of group that contains drawable objects. See also ordered display group, proxy display group.

distance buttonA button in the controller strip of a viewer object that, when clicked, puts the cursor into trucking mode. Subsequent dragging up or down in the picture area causes the object to move farther away or closer. Compare camera angle button, move button, rotate button, zoom button.

DOFSee degrees of freedom.

dot productThe floating-point number obtained by multiplying corresponding scalar components of two vectors and then adding together all those products. The dot product of the vectors u and v is denoted
u × v. Compare cross product.

drawable flagA group state flag that determines whether a group is to be drawn when it is passed to a view for rendering or picking. Compare inline flag, picking flag.

draw contextSee draw context object.

draw context coordinate systemSee window coordinate system.

draw context data structureA data structure that contains basic information about a draw context. Defined by the TQ3DrawContextData data type.

draw context objectA QuickDraw3D object that maintains information specific to a particular window system or drawing destination. A draw context object is an instance of the TQ3DrawContextObject class. See also Macintosh draw context, pixmap draw context.

draw context spaceSee window coordinate system.

drawing destinationThe window
or other output destination for a
rendered model.

edgeA straight line that connects two vertices. See also mesh edge.

edge toleranceA measure of how close a point must be to a line for a hit to occur. Compare vertex tolerance.

elementSee element object.

element objectAny QuickDraw3D
object that can be part of a set. An
element object is an instance of the TQ3ElementObject class.

elevation projectionA type of orthographic projection in which the view plane is perpendicular to one of the principal axes of the object being projected. See also front elevation projection, side elevation projection, top elevation projection. Compare isometric projection.

errorA nonrecoverable condition that causes the currently executing QuickDraw3D routine to fail. See also fatal error, notice, warning.

Error ManagerThe part of QuickDraw3D that you can use to handle any errors or other exceptional conditions that occur during the execution of QuickDraw3D routines.

even-odd ruleA method of determining which planar areas defined by an arbitrary list of vertices are inside a polygon. To determine whether a particular bounded region is inside or outside a polygon, shoot a ray from any point in that region in any direction that does not intersect any vertex. If the ray cuts an odd number of edges, that region is inside the polygon; if the ray cuts an even number of edges, that region is outside the polygon.

eye pointSee camera location.

faceA closed figure that forms part of the surface of an object. Usually faces are planar, but mesh faces do not need to be planar. See also mesh face.

face attributeAn attribute that defines a characteristic of a polygonal object.

face indexIn a mesh, a unique integer (between 0 the total number of faces in the mesh minus 1) associated with a face. Compare vertex index.

facetSee face.

faceted shadingSee constant shading.

fall-off valueA measure of the attenuation of a spot light's intensity from the edge of the hot angle to the edge of the outer angle. See also hot angle, outer angle.

far planeSee yon plane.

fatal errorAn error whose effects persist even after the call that caused it has ended.

field of viewThe horizontal or vertical angular expanse visible through a camera. See also aspect ratio camera.

fileSee file object.

file idle methodA callback routine that is called during lengthy file operations. Compare view idle method.

file modeA set of flags that determine which operations can be performed on a piece of storage.

file mode flagA value used to construct a file mode.

file objectA type of QuickDraw3D object that you can use to access disk- or memory-based data stored in a container.
A file object is an instance of the TQ3FileObject class. See also storage object.

file status valueA value returned by the Q3File_EndWrite function that indicates whether QuickDraw3D has finished writing the model to a file object.

fill styleA type of QuickDraw3D object that determines whether an object is drawn as a solid filled object or is decomposed into its components (namely, into a set of edges or points).

flat shadingSee constant shading.

frameSee viewer pane.

front clipping planeSee hither plane.

front elevation projectionA type of elevation projection in which the view plane is parallel to the front of the object being projected.

frustumA solid figure created by cutting a cone or pyramid with two parallel planes. Compare view frustum.

frustum coordinate systemSee camera coordinate system.

frustum spaceSee camera coordinate system.

frustum-to-window transformA transform that defines the relationship between a frustum coordinate system and a window coordinate system. Compare local-to-world transform, world-to-
frustum transform
.

general polygonA closed plane figure defined by one or more lists of vertices (that is, defined by one or more contours). Defined by the TQ3GeneralPolygonData data type. See also simple polygon.

generic rendererA renderer that you can use solely to collect state information. The generic renderer does not draw any image.

geometric objectA type of QuickDraw3D object that describes a particular kind of drawable shape, such as a triangle or a box. A geometric object is an instance of the TQ3GeometryObject class. See also box, general polygon, line, marker, mesh, NURB curve, NURB patch, point, polygon, triangle, trigrid.

geometric primitiveAny of the basic geometric objects defined by QuickDraw3D.

geometrySee geometric object.

geometry attributeAn attribute that defines a characteristic of a nonpolygonal geometric object.

global coordinate systemSee world coordinate system.

global spaceSee world coordinate system.

Gouraud shadingA method of shading surfaces in which the incident light color and intensity are calculated for each vertex of a polygon and then interpolated linearly across the entire polygon. Compare constant shading, Phong shading.

graphics acceleratorAny hardware device used by QuickDraw3D to
accelerate rendering.

groupSee group object.

group objectA type of QuickDraw3D object that you can use to collect objects together into hierarchical models. A
group object is an instance of the TQ3GroupObject class.

group positionA pointer to a data structure maintained internally by QuickDraw3D that indicates the position
of a group element in the group.

group state flagA value that indicates the state of some characteristic of a group.

group state valueA set of group state flags that determine how a group is traversed during rendering or picking, or during computation of its bounding box
or sphere.

handle storage objectA storage object that represents a handle to a dynamically allocated block of RAM.

hidden line removalThe process of removing any lines in a model that are hidden by opaque surfaces of objects.

hidden surface removalThe process of removing any surfaces in a model that are hidden by opaque surfaces of objects. Compare backface culling.

hierarchySee QuickDraw3D class hierarchy.

highlight stateAn attribute having data of type TQ3Boolean that determines whether a highlight style overrides the material attributes of an object (kQ3True)
or not.

highlight styleA type of QuickDraw3D object that determines the material attributes of a geometric object (or a group of geometric objects) that override the normal attributes of the object (or group
of objects).

high-order bitSee most significant bit.

hitAn object in a model that is close enough to the pick geometry. See also
hit list.

hit data structureA data structure that contains information about a hit. Defined by the TQ3HitData data type.

hither planeThe clipping plane closest to the camera.

hit information maskA value that indicates the type of information you want returned for the items in a hit list.

hit listA list of all objects in a model that are close to the pick geometry.

hit list sorting valueA value that determines the kind of sorting that is to be done on a hit list.

hit path structureA data structure that contains information about the path through a model hierarchy to a specific picked object. Defined by the TQ3HitPath data type.

hit testingSee picking.

hot angleThe half-angle (specified in radians) from the center of a spot light's cone of light within which the light remains at constant full intensity. See also fall-off value, outer angle.

identity matrixAny n n square matrix with elements aij such that aij = 1 if i = j and aij = 0 otherwise. Compare inverse.

idle methodSee file idle method, view idle method.

illumination shaderA shader that determines the effects of the view's group of lights on the objects in a model. Compare Lambert illumination shader, Phong illumination shader.

imageThe two-dimensional product of rendering.

image plane structureA data structure that contains information about an image plane. Defined by the TQ3ImagePlane
data type.

immediate modeA mode of defining and rendering a model in which the application maintains the only copy of the model data. See also retained mode.

immediate objectAn object that is rendered in immediate mode. See also retained object.

infinite lightSee directional light.

information groupA group that contains one or more strings (and no other types of QuickDraw3D objects).

inheritTo have the data and methods
of a parent class apply to a child class. Compare override.

inheritanceThe property of the QuickDraw3D class hierarchy whereby a child class inherits the data and methods of its parent class.

initial lineSee polar axis.

inlineA method of executing groups that does not push and pop the graphics state stack before and after it is executed.

inline flagA group state flag that determines whether or not a group should be executed inline. Compare drawable flag, picking flag.

inner productSee dot product.

input/output (I/O)The parts of a computer system that transfer data to or from peripheral devices.

instantiable classA class of which instances can be created. All leaf classes are instantiable, and many parent classes are instantiable as well. (For example, both the class TQ3AttributeSet and its parent class TQ3SetObject are instantiable.)

interactingThe process of selecting and manipulating objects in a model.

interactive rendererA renderer that uses a fast and accurate algorithm for drawing solid, shaded surfaces. See also wireframe renderer.

interpolated shadingSee Gouraud shading.

interpolation styleA type of QuickDraw3D object that determines the method of interpolation a renderer uses when applying lighting or other shading effects to a surface.

intersectionThe set of points that lie inside both of two given solid objects. The intersection of the objects A and B is represented by the function A << B. Compare complement, union.

inverseFor an n n square matrix A with a nonzero determinant, the matrix B such that AB = BA =I, where I is the n n identity matrix.

inverse matrixSee inverse.

I/OSee input/output.

I/O proxy display groupA display group that contains several representations of a single geometric object.

isometric projectionA type of orthographic projection in which the view plane is not perpendicular to any of the principal axes of the object being projected but makes equal angles with each of those axes. Compare elevation projection.

join pointSee knot.

knotA point on a curve that joins two segments of the curve.

knot vectorAn array of numbers that defines a curve's knots.

Lambertian reflectionSee diffuse reflection.

Lambert illuminationA method of calculating the illumination of a point on
a surface based on diffuse reflection. Compare null illumination, Phong illumination.

Lambert illumination shaderAn illumination shader that implements a Lambert illumination model. Compare null illumination shader, Phong illumination shader.

leaf classA class that has no children.

leaf objectAn instance of a leaf class.

leaf typeThe object type of a leaf object.

least significant bit (LSB)The bit contributing the least value in a string of bits. Same as low-order bit. Compare most significant bit.

left-handed coordinate systemA coordinate system that obeys the left-hand rule. In a left-handed coordinate system, positive rotations of an axis are clockwise. Compare right-handed coordinate system.

left-hand ruleA method of determining the direction of the positive z axis (and thereby the front of a planar surface). According to the left-hand rule, if the thumb of the left hand points in the direction of the positive x axis and the index finger points in the direction of the positive y axis, then the middle finger points in the direction of the positive z axis. Compare right-hand rule.

lightSee light object.

light attenuationSee attenuation.

light data structureA data structure that contains basic information about a light. Defined by the TQ3LightData data type.

light fall-offSee fall-off value.

light groupA group that contains one or more lights (and no other types of QuickDraw3D objects).

light objectA type of QuickDraw3D object that you can use to illuminate the surfaces in a model. A light object is an instance of the TQ3LightObject class.
See also ambient light, directional light, point light, spot light.

lineA straight segment in three-
dimensional space defined by its two endpoints, with an optional set of attributes. Defined by the TQ3LineData data type.

line of projectionSee projector.

little-endianData formatting in which each field is addressed by referring to its least significant byte. See also big-endian.

local coordinate systemThe coordinate system in which an individual geometric objects is defined. Also called the object coordinate system or the modeling coordinate system. Compare camera coordinate system, window coordinate system, world coordinate system.

local spaceSee local coordinate system.

local-to-world transformA transform that defines the relationship between an object's local coordinate system and the world coordinate system. Compare frustum-to-window transform, world-to-
frustum transform
.

low-order bitSee least significant bit.

LSBSee least significant bit.

luminanceThe intensity of light in a color.

Macintosh draw contextA draw context that is associated with a Macintosh window.

Macintosh draw context data structureA data structure that contains information about a Macintosh draw context. Defined by the TQ3MacDrawContextData data type.

Macintosh FSSpec storage objectA storage object that represents the data fork of a Macintosh file using a file system specification structure (of type FSSpec).

Macintosh storage objectA storage object that represents the data fork of a Macintosh file using a file reference number. Compare Macintosh FSSpec storage object.

mappingThe process of transforming one coordinate space into another.

markerA two-dimensional object typically used to indicate the position of an object (or part of an object) in a window. Defined by the TQ3MarkerData data type.

matrixA rectangular array of numbers. QuickDraw3D defines 3-by-3 and 4-by-4 matrices using the TQ3Matrix3x3 and TQ3Matrix4x4 data types.

matrix transformAny transform specified by an affine, invertible 4-by-4 matrix.

memory storage objectA storage object that represents a dynamically allocated block of RAM. Compare handle storage object.

meshA collection of vertices, faces, and edges that represent a topological polyhedron. Defined by the TQ3Mesh
data type.

mesh componentA collection of connected vertices in a mesh. Defined by the TQ3MeshComponent data type.

mesh cornerA mesh face together with one of its vertices. You can associate a set of attributes with a mesh corner. The attributes in a corner override any existing attributes of the associated vertex.

mesh edgeA line that connects two mesh vertices. A mesh edge is part of one or more mesh faces. Defined by the TQ3MeshEdge data type.

mesh faceA closed figure that forms part of a mesh. Unlike the faces of other geometric objects, mesh faces do not need to be planar. Defined by the TQ3MeshFace data type.

mesh iterator structureA data structure used by QuickDraw3D to maintain information when iterating through parts of a mesh. Defined by the TQ3MeshIterator data type.

mesh partSee mesh part object.

mesh part objectA distinguishable part of a mesh. A mesh part object is an instance of the TQ3MeshPartObject class.

mesh vertexA vertex (that is, a three-dimensional point) that is contained in a mesh. Defined by the TQ3MeshVertex data type.

metafileA file format (that is, a description of the format of a kind of file). See also QuickDraw3D Object Metafile.

metafile objectA basic unit contained in a file that conforms to the QuickDraw3D Object Metafile.

metahandlerAn application-defined function that QuickDraw3D calls to build
a method table for a custom object type. Compare attribute metahandler.

methodAn item of data associated with a particular object class. The data is usually a function pointer or other information used by the object class.

metric pickSee metric pick object.

metric pick objectA pick object whose pick geometry has a pick origin.

modelA collection of synthetic three-
dimensional geometric objects and groups of geometric objects. A model represents
a prototype.

modelingThe process of creating a representation of real or abstract objects.

modeling coordinate systemSee local coordinate system.

modeling spaceSee local coordinate system.

most significant bit (MSB)The bit contributing the greatest value in a string of bits. Same as high-order bit. Compare least significant bit.

move buttonA button in the controller strip of a viewer object that, when clicked, puts the cursor into move mode. Subsequent dragging on an object in the picture area causes the object to be moved to a new location. Compare camera angle button, distance button, rotate button, zoom button.

MSBSee most significant bit.

natural attributeAn attribute that can naturally be contained in a set of attributes of a specific type.

natural surface parameterizationA parameterization of a surface that can be derived directly from the definition of the surface. Compare custom surface parameterization, standard surface parameterization.

near planeSee hither plane.

nonuniform rational B-spline (NURB)
A curve defined by nonuniform parametric ratios of B-spline polynomials. NURB curves can be used to define very complex curves and surfaces, as well as very common geometric objects (for instance, the conic sections). See also control point, knot, NURB curve, NURB patch.

normal(a.) Perpendicular. (n.) A normal vector.

normal fileA metafile in which the specification of an object in the file never occurs more than once. In other words, a file object that contains a table of contents that lists all multiply-referenced objects in the file. See also normal file, stream file.

normalized vectorA vector whose length is 1.

normal modeThe mode in which a normal file is opened. See also database mode, stream mode.

normal vectorA vector that is normal (that is perpendicular) to a surface or planar object at a specific point.

noticeA condition that is less severe than a warning, and that will likely not cause problems. See also error, warning.

notify functionSee tracker notify function.

null illuminationA method of calculating the illumination of a point on a surface that depends only on the diffuse color of the point. Compare Lambert illumination, Phong illumination.

null illumination shaderAn illumination shader that implements a null illumination model. Compare Lambert illumination shader, Phong illumination shader.

NURBSee nonuniform rational B-spline.

NURB curveA three-dimensional curve represented by a NURB equation. Defined by the TQ3NURBCurveData data type.

NURB patchA three-dimensional surface represented by a NURB equation. Defined by the TQ3NURBPatchData data type.

object(1) See QuickDraw3D object. (2) See metafile object.

object coordinate systemSee local coordinate system.

object spaceSee local coordinate system.

object typeThe identifier of the class of which a QuickDraw3D object is an instance. Also called the class type.

oblique projectionA type of parallel projection in which the view plane is not perpendicular to the viewing direction. Compare orthographic projection.

off-axis viewingA method of perspective projection in which the center of the projected object on the view plane is not on the camera vector.

opaque(1) For a data structure, not publicly defined. You must use QuickDraw3D functions to get and set values in an opaque data structure. For an object, having data and methods that are not publicly defined. (2) For a geometric object, not allowing light to pass though.

openSaid of a storage object whenever its associated storage is in use--for example, when an application is reading data from a file object attached to the storage object.

orderFor a NURB curve or patch, one more than the highest degree equation used to define the curve or patch. For example, the order of a NURB curve defined by cubic polynomial equations is 4.

ordered display groupA display group in which the objects in the group are sorted by their type.

orientation styleA type of QuickDraw3D object that determines which side of a planar surface is considered to be the "front" side.

originIn Cartesian coordinates, the point (0, 0) or (0, 0, 0). The coordinate axes intersect at the origin.

original QuickDrawSee QuickDraw.

orthogonalPerpendicular.

orthographic cameraA type of camera that uses orthographic projection.

orthographic camera data structure
A data structure that contains basic information about an orthographic
camera. Defined by the TQ3OrthographicCameraData data type.

orthographic projectionA type of parallel projection in which the view plane is perpendicular to the viewing direction. Compare oblique projection. See also elevation projection, isometric projection.

outer angleThe half-angle (specified in radians) from the center of a spot light's cone to the edge of the cone. See also fall-off value, hot angle.

outer productSee cross product.

overrideTo define class data or methods that replace those of the parent class. Compare inherit.

parallel projectionA method of projecting a model onto a viewing plane that uses parallel projectors. See also oblique projection, orthographic projection. Compare perspective projection.

parameterizationA parametric function that picks out all points on a geometric object, such as a pixmap or a surface. Compare surface parameterization.

parametric curveAny curve whose points are described by one or more parametric functions. A two-dimensional parametric curve can be described by the parametric functions x = x(t) and y = y(t). A three-
dimensional parametric curve is described by the parametric functions x = x(t), y = y(t), and z = z(t). Compare B-spline polynomial, nonuniform rational B-spline (NURB).

parametric equationSee parametric function.

parametric functionA function of one or more parameters (often denoted by s and t or u and v).

parametric pointA position in two- or three-dimensional space picked out by a parametric function. Defined by the TQ3Param2D and TQ3Param3D data types. Compare point, point object, rational point.

parent classThe class (if any) of which a given class is a subclass. In other words, a class' parent class is the class immediately above that class in the QuickDraw3D class hierarchy. For example, the shape class is the parent class of the light class. Also called a base class or a superclass.

patchA portion of a surface defined by a set of points. Compare NURB patch.

perspective foreshorteningA feature of perspective projections wherein the size of
a projected object varies inversely with
the distance of the object from the center
of projection.

perspective projectionA method of projecting a model onto a viewing plane that uses nonparallel projectors. Compare parallel projection.

Phong illuminationA method of calculating the illumination of a point on a surface based on both diffuse reflection and specular reflection. Compare Lambert illumination, null illumination.

Phong illumination shaderAn illumination shader that implements a Phong illumination model. Compare Lambert illumination shader, null illumination shader.

Phong shadingA method of shading surfaces in which the incident light color and intensity are calculated for a series of points along each edge of a polygon and then interpolated across the entire polygon. Compare constant shading, Gouraud shading.

pick(n.) See pick object. (v.) To determine whether a specified object is close enough to a pick geometry for a hit to be recorded.

pick data structureA data structure that contains basic information about a pick object. Defined by the TQ3PickData
data type.

pick detailSee hit information mask.

pick geometryThe geometric object used in any picking method.

pick hitSee hit.

pick hit listSee hit list.

pickingThe process of identifying the objects in a view that are close to a specified geometric object.

picking flagA binary flag in a group state value that determines whether a group is eligible for picking. Compare drawable flag, inline flag.

picking IDAn arbitrary 32-bit value that you can use to determine which object was selected by a pick operation.

picking ID styleA type of style object that determines the picking ID of an object or group of objects in a model.

picking loopA section of code in which all picking takes place. A picking loop begins with a call to the Q3View_StartPicking routine and should end when a call to Q3View_EndPicking returns some value other than kQ3ViewStatusRetraverse. A picking
loop is a type of submitting loop. See
also bounding loop, rendering loop, writing loop.

picking parts styleA type of QuickDraw3D object that determines which parts of a geometric object (for instance, a mesh) are eligible for inclusion in a hit list.

pick objectA QuickDraw3D object that is used to select geometric objects in a model that are close to a specified geometric object. A pick object is an instance of the TQ3PickObject class.

pick originA point in space that determines the origin of sorting hits. Compare metric pick object.

pick parts maskA value that indicates the kinds of objects placed in a hit list.

picture areaThe portion of a window occupied by a viewer object that contains the displayed image.

pixel imageSee pixmap

pixel mapSee pixmap

pixmapA two-dimensional array of values, each of which represents the color of one pixel. Defined by the TQ3Pixmap data type. See also bitmap, storage pixmap.

pixmap draw contextA draw context that is associated with a pixmap.

pixmap draw context data structureA data structure that contains information about a pixmap draw context. Defined by the TQ3PixmapDrawContextData data type.

pixmap texture objectA texture object in which the texture is defined by a pixmap.

planarContained completely in two dimensions (as, for example, a circle). See also spatial.

plane constantThe value d in the plane equation ax+by+cz+d = 0.

plan elevation projectionSee top elevation projection.

plane equationAn equation that defines
a plane. A plane equation can always be reduced to the form ax+by+cz+d = 0. Defined by the TQ3PlaneEquation
data type.

pointA dimensionless position in two- or three-dimensional space. Defined by the TQ3Point2D and TQ3Point3D data types. Compare parametric point, point object, rational point.

point lightA light source that emits rays of light in all directions from a specific location.

point light data structureA data structure that contains information about a point light. Defined by the TQ3PointLightData data type.

point objectA dimensionless position in three-dimensional space, with an optional set of attributes. Defined by the TQ3PointData data type.

point of interestThe point in world space at which a camera is aimed. The point of interest and the camera location determine the viewing direction.

point pick objectSee window-point
pick object.

polar coordinate systemA system of assigning planar positions to objects in terms of their distances (r) from a point (the polar origin, or pole) along a ray that forms a given angle (q) with a coordinate line (the polar axis). The polar origin has the polar coordinates (0, q), for any angle q. Compare Cartesian coordinate system, spherical coordinate system.

polar axisA fixed ray that radiates from the polar origin, in terms of which polar coordinates are determined. Also called the initial line.

polar originThe point in a plane from which the polar axis radiates. Also called the pole.

polar pointA point in a plane described using polar coordinates.

poleSee polar origin.

polygonA closed plane figure. See general polygon, simple polygon.

polygon meshA mesh whose faces are composed of polygons.

polyhedronA solid figure composed
of faces.

postmultipliedA term that describes the order in which matrices are multiplied. Matrix [A] is postmultiplied by matrix [B]
if matrix [A] is replaced by [A] [B]. Compare premultiplied.

premultipliedA term that describes the order in which matrices are multiplied. Matrix [A] is premultiplied by matrix [B] if matrix [A] is replaced by [B] [A]. Compare postmultiplied.

primitiveSee geometric primitive.

privateSee opaque.

projection(1) A method of mapping three-dimensional objects into two dimensions. See also parallel projection, perspective projection. Compare camera object. (2) The image on the view plane that results from mapping three-dimensional objects into two dimensions.

projection planeSee view plane.

projective transformSee frustum-to-window transform.

projectorA ray that intersects both a point on an object in a model and the view plane, thereby projecting the object in the model onto the view plane.

prototypeThe object (or collection of objects) represented in a model. Compare model, synthetic.

prototypicalOf or pertaining to a prototype. Compare model, synthetic.

proxy display groupSee I/O proxy display group.

quaternionA quadruple of floating-point numbers that obeys the laws of quaternion arithmetic. Defined by the TQ3Quaternion data type.

quaternion transformA type of transform that rotates and twists an object according to the mathematical properties of quaternions.

QuickDrawA collection of system software routines on Macintosh computers that perform two-dimensional drawing on the user's screen.

QuickDraw3DA graphics library developed by Apple Computer, Inc., that you can use to create, configure, render, and interact with models of three-dimensional objects. You can also use QuickDraw3D to read and write 3D data.

QuickDraw3D classA structure for the data that characterize QuickDraw3D objects, together with a set of methods
that operate on that data. Compare QuickDraw3D object. See also child class, leaf class, parent class.

QuickDraw3D class hierarchyThe hierarchical arrangement of QuickDraw3D object classes.

QuickDraw3D objectAny instance of a QuickDraw3D class. See also object type.

QuickDraw3D Object Metafile (3DMF)
An extensible file format defined by Apple Computer, Inc., for storing 3D data and interchanging 3D data between applications.

QuickDraw3D Pointing Device Manager
A set of functions that you can use to manage three-dimensional pointing devices.

QuickDraw3D shading architecture
An environment in which shaders can
be applied at various stages in the
imaging pipeline.

radius vectorThe ray that radiates from the polar origin and that forms a given angle with the polar axis (or two given angles with the x and z axes). A polar or spherical point lies at a given distance along the radius vector. See also polar coordinate system, spherical coordinate system.

rasterizationThe process of determining values for the pixels in a rendered image. Also called scan conversion.

rational pointA dimensionless position in two- or three-dimensional space together with a floating-point weight. Defined
by the TQ3RationalPoint3D and TQ3RationalPoint4D data types.
Compare point.

rayA point of origin and a direction. Defined by the TQ3Ray3D data type.

realSee prototypical.

rectangle pick objectSee window-rectangle pick object.

reference countThe number of times a shared object is being accessed.

renderTo create an image (on the screen or some other medium) of a model.

rendererSee renderer object.

renderer objectA QuickDraw3D object that you can use to render a model--that is, to create an image from a view and a model. A renderer object is an instance of the TQ3RendererObject class.

renderingThe process of creating an image (on the screen or some other medium) of a model. See also rasterization.

rendering loopA section of code in
which all rendering takes place. A rendering loop begins with a call to the Q3View_StartRendering routine and should end when a call to Q3View_EndRendering returns some value other than kQ3ViewStatusRetraverse. A rendering loop is a type of submitting loop. See also bounding loop, picking loop, writing loop.

retained modeA mode of defining and rendering a model in which the graphics library (for instance, QuickDraw3D) maintains a copy of the model. See also immediate mode.

retained objectAn object that is defined and rendered in retained mode. See also immediate object.

RGB color spaceA color space whose three components measure the intensity of red, green, and blue.

RGB color structureA data structure that contains information about a color. Defined by the TQ3ColorRGB data type.

right-handed coordinate systemA coordinate system that obeys the right-hand rule. In a right-handed coordinate system, positive rotations of an axis are counterclockwise. Compare left-handed coordinate system.

right-hand ruleA method of determining the direction of the positive z axis (and thereby the front of a planar surface). According to the right-hand rule, if the thumb of the right hand points in the direction of the positive x axis and the index finger points in the direction of the positive y axis, then the middle finger points in the direction of the positive z axis. Compare left-hand rule.

rotateTo reposition an object by revolving (or turning) each point of the object by the same angle around a point or axis.

rotate-about-axis transformA type of transform that rotates an object about an arbitrary axis in space by a specified number of radians at an arbitrary point
in space.

rotate-about-axis transform data structureA data structure that contains information on a rotate transform about
an arbitrary axis in space at an arbitrary point in space. Defined by the TQ3RotateAboutAxisTransformData
data type.

rotate-about-point transformA type of transform that rotates an object about the x, y, or z axis by a specified number of radians at an arbitrary point in space.

rotate-about-point transform data structureA data structure that contains information on a rotate transform about
an arbitrary point in space. Defined by
the TQ3RotateAboutPointTransformData data type.

rotate buttonA button in the controller strip of a viewer object that, when clicked, puts the cursor into rotate mode. Subsequent dragging of the cursor in the picture area causes the displayed object
to rotate in the direction in which the
cursor is dragged. Compare camera angle button, distance button, move button, zoom button.

rotate transformA type of transform that rotates an object about the x, y, or z axis at the origin by a specified number of radians.

rotate transform data structureA data structure that contains information about
a rotate transform. Defined by the TQ3RotateTransformData data type.

rotationA transform that causes an object to revolve around a point or an axis. Compare rotate-about-axis transform, rotate-about-point transform, rotate transform.

scalar productSee dot product.

scaleTo reposition and resize an object by multiplying the x, y, and z coordinates of each of its points by values dx, dy, and dz. Compare differential scaling, uniform scaling.

scale transformA type of transform that scales an object along the x, y, and z axes by specified values.

scan conversionSee rasterization.

sceneA combination of objects, lights, and draw context.

screen coordinate systemSee window coordinate system.

screen spaceSee window coordinate system.

screen-space pickingThe process of testing whether the projections of three-
dimensional objects onto the screen intersect or are close enough to a specified two-dimensional object on the screen.

screen-space subdivisionA method of subdividing smooth curves and surfaces.
In this method, the renderer subdivides a curve (or surface) into polylines (or polygons) whose sides have a maximum length of some specified number of pixels. Compare constant subdivision, world-space subdivision.

serpentineSaid of a trigrid in which quadrilaterals are divided into triangles in an alternating fashion.

setSee set object.

set objectA collection of zero or more elements, each of which has both an element type and some associated element data. A set object is an instance of the TQ3SetObject class.

shaderSee shader object.

shader objectA type of QuickDraw3D object that you can use to manipulate visual effects that depend on the illumination provided by a view's group of lights, the color and other material properties (such as the reflectance and texture) of surfaces in a model, and the position and orientation of the lights and objects in a model. A shader object is an instance of the TQ3ShaderObject class.

shading parameterizationA surface
uv parameterization used when shading
a surface.

shadow-receiving styleA type of QuickDraw3D object that determines whether or not objects in a model receive shadows when obscured by other objects
in the model.

shapeSee shape object.

shape objectA type of QuickDraw3D object that affects how and where a renderer renders an object in a view. A shape object is an instance of the TQ3ShapeObject class.

shape partSee shape part object.

shape part objectA distinguishable part of a shape object. A shape part object is an instance of the TQ3ShapePartObject class. See also mesh part object.

shared objectA QuickDraw3D object that may be referenced by many objects or the application at the same time. A shared object is an instance of the TQ3SharedObject class.

side elevation projectionA type of elevation projection in which the view plane is parallel to a side of the object
being projected.

simple polygonA closed plane figure defined by a list of vertices (that is, defined by a single contour). Defined by the TQ3PolygonData data type. See also general polygon.

smooth shadingSee Gouraud shading, Phong shading.

space(1) See coordinate system. (2) The two- or three-dimensional extent defined by a coordinate system.

spatialContained completely in three dimensions (as, for example, a box). See also planar.

specular coefficientA measure of an object's level of specular reflection.

specular colorThe color of the light of a specular reflection.

specular controlSee specular reflection exponent.

specular exponentSee specular reflection exponent.

specular highlightA bright area on
an object's surface caused by specular reflection.

specular reflectionThe type of reflection that is characteristic of light reflected from a shiny surface. Compare diffuse reflection.

specular reflection coefficientSee specular coefficient.

specular reflection exponentA value that determines how quickly the specular reflection diminishes as the viewing direction moves away from the direction of reflection.

spherical coordinate systemA system of assigning spatial positions to objects in terms of their distances from the origin (r) along a ray that forms a given angle (q) with the x axis and another angle (f) with the z axis. Compare Cartesian coordinate system, polar coordinate system.

spherical pointA point in space described using spherical coordinates.

spot lightA light source that emits a circular cone of light in a specific direction from a specific location. See also fall-off value, hot angle, outer angle.

spot light data structureA data structure that contains information about a spot
light. Defined by the TQ3SpotLightData data type.

standard I/O libraryA collection of functions that provide character I/O and file manipulation services for C programs. Compare UNIX storage object.

standard surface parameterizationA parametric function that maps the unit square to an object's surface. Compare custom surface parameterization, natural surface parameterization.

storage objectA QuickDraw3D object that represents any piece of storage in a computer (for example, a file on disk, an area of memory, or some data on the Clipboard). A storage object is an instance of the TQ3StorageObject class.

storage pixmapA two-dimensional array of values contained in a storage object, each of which represents the color of one pixel. Defined by the TQ3StoragePixmap data type. See also bitmap, pixmap.

stream fileA metafile that contains no internal references. In other words, a file object that does not contain a table of contents and in which any references to objects are simply copies of the objects themselves. See also normal file, stream file.

stream modeThe mode in which a stream file is opened. See also database mode, normal mode.

stringSee string object.

string objectA QuickDraw3D object
that contains a sequence of characters.
A string object is an instance of the TQ3StringObject class. See also C
string object.

styleSee style object.

style objectA type of QuickDraw3D object that determines some of the basic characteristics of the renderer used to render the curves and surfaces in a scene. A style object is an instance of the TQ3StyleObject class.

subclassSee child class.

subdivision methodA method of subdividing smooth curves and surfaces. See constant subdivision, screen-space subdivision, world-space subdivision.

subdivision method specifierAn indicator of the number of parts into
which a smooth curve or surface is to
be subdivided.

subdivision styleA type of QuickDraw3D object that determines how a renderer decomposes smooth curves and surfaces into polylines and polygonal meshes for display purposes.

subdivision style data structureA data structure that contains information about the type of subdivision of curves and surfaces used by a renderer. Defined by the TQ3SubdivisionStyleData data type.

submitTo make an object (or group of objects) eligible for drawing, picking, writing, or bounding box or sphere calculation. Compare submitting loop.

submitting loopA section of code in which all submitting takes place. Compare bounding loop, picking loop, rendering loop, writing loop.

superclassSee parent class.

surface-based shaderA shader that affects the surfaces of geometric objects based on their material properties, position, and orientation (and other factors). Compare view-based shader.

surface parameterizationA parametric function that picks out all points on a surface. See also custom surface parameterization, natural surface parameterization, standard surface parameterization.

surface normalSee normal vector.

surface shaderA shader that is applied when calculating the appearance of a surface. Compare texture shader.

surface tangentA pair of vectors that indicate the directions of changing u and v parameters on a surface. Defined by the TQ3Tangent2D data type.

surrounding lightSee ambient light.

syntheticNot real, as for example the objects in a model. Compare prototypical.

synthetic cameraSee camera object.

tangentA line or plane that intersects a curve or surface at a single point. Compare surface tangent.

tessellateTo decompose a curve or surface into polygonal faces.

text fileA file object whose data is a stream of ASCII characters with meaningful labels for each type of object contained in the file. Compare binary file.

textureSee texture object.

texture mappingA technique wherein a predefined image (the texture) is mapped onto the surface of an object in a model.

texture objectA type of QuickDraw3D object used to perform texture mapping. Compare pixmap texture object.

texture parameterizationA parametric function that maps the unit square to
a texture.

texture shaderA type of surface shader that applies textures to surfaces.

toleranceSee edge tolerance, vertex tolerance.

top elevation projectionA type of elevation projection in which the view plane is parallel to the top of the object being projected. Also called plan elevation projection.

trackerSee tracker object.

tracker coordinatesThe current settings (that is, position and orientation) of
a tracker.

tracker notify functionA function that is called whenever the coordinates of a tracker change by more than a specified amount.

tracker objectA QuickDraw3D object that represents the position and orientation of a single element in your application's user interface. A tracker object is an instance of the TQ3TrackerObject class. See also controller object.

tracker serial numberA unique number that changes every time the coordinates of a tracker are updated by a controller.

tracker thresholdThe amount by which
a tracker's coordinates must change for
the tracker notify function to be called.

transformSee transform object.

transform objectA type of QuickDraw3D object that you can use to modify or transform the appearance or behavior of a QuickDraw3D object. A transform object is an instance of the TQ3TransformObject class.

translateTo reposition an object by adding values dx, dy, and dz to the x, y, and z coordinates of each of its points.

translate transformA type of transform that translates an object along the x, y, and z axes by specified values.

transparencyThe ability of an object to allow light to pass through it.

transparency colorA color of type TQ3ColorRGB that determines the amount of light that can pass through a surface.
The color (0, 0, 0) indicates complete transparency, and (1, 1, 1) indicates complete opacity.

transpose(n.) For an m n matrix with elements aij, the n m matrix with elements bij such that bij = aji. (v.) To form the transpose of a given matrix.

transpose matrixSee transpose.

triangleA closed plane figure defined by three edges. Defined by the TQ3TriangleData data type.

trigridA grid composed of triangular facets. Defined by the TQ3TriGridData
data type.

typeSee object type.

under-color shaderA shader associated with some other shader that supplies an under color for surfaces shaded by that shader.

uniform scalingA scale transform in which the scaling values dx, dy, and dz are all identical. Compare differential scaling.

unionThe set of points that lie inside either of two given solid objects. The union of the objects A and B is represented by the function A È B. Compare complement, intersection.

unit cubeA box whose three defining edges have a length of 1.

unit vectorSee normalized vector.

UNIX path name storage objectA storage object that represents a file using a
path name.

UNIX storage objectA storage object that represents a file using a structure of type FILE (defined in the standard I/O library). Compare UNIX path name storage object.

unknown objectA type of QuickDraw3D object that is created when QuickDraw3D encounters data it doesn't recognize while reading a metafile. An unknown object is an instance of the TQ3UnknownObject class.

up vectorA vector that indicates which direction is up. A camera has an up vector that defines its orientation. Compare camera placement.

user interface viewSee user interface view object.

user interface view notify functionA function that is called whenever one of your user interface views needs to be redrawn.

user interface view objectA type of view that allows the user to interact (using interface elements such as a 3D cursor or widgets) with the 3D objects displayed in the view. A user interface view object is an instance of the TQ3UIViewObject class.

valid rangeThe range of u and v parametric values for a standard surface parameterization. For QuickDraw3D, the valid range is the closed interval [0.0, 1.0].

vectorA pair or triple of floating-point numbers that obeys the laws of vector arithmetic. Defined by the TQ3Vector2D and TQ3Vector3D data types. Compare cross product, dot product, normal.

vector-normal interpolation shadingSee Phong shading.

vector productSee cross product.

vertexA dimensionless position in three- or four-dimensional space at which two or more lines (for instance, edges) intersect, with an optional set of vertex attributes. Defined by the TQ3Vertex3D and TQ3Vertex4D data types. See also mesh vertex.

vertex attributeAn attribute that defines
a characteristic of a vertex of a
polygonal object.

vertex indexIn a mesh, a unique integer (between 0 the total number of vertices in the mesh minus 1) associated with a vertex. Compare face index.

vertex toleranceA measure of how close two points must be for a hit to occur. Compare edge tolerance.

viewSee view object.

view attributeAn attribute that defines a characteristic of a view object.

view-based shaderA shader that operates independently of the material properties or orientation of objects (in other words, that operates solely on aspects of the view, such as the camera position). Compare surface-
based shader.

viewing boxThe rectangular box defined by an orthographic camera and the hither and yon clipping planes. Compare viewing frustum.

view coordinate systemSee camera coordinate system.

viewerSee viewer object.

ViewerSee 3D Viewer.

viewer badgeSee badge.

viewer controller stripSee controller strip.

viewer flagsA set of bit flags that specify information about the appearance and behavior of a viewer object.

viewer frameSee viewer pane.

viewer objectAn instance of the 3D Viewer. A viewer object is of type ViewerObject.

viewer paneThe portion of a window occupied by a viewer object. The pane includes the picture area and the controller strip.

viewer state flagsA set of bit flags returned by the Q3ViewerGetState function that specify information about the current state of a viewer object.

viewing frustumThe rectangular frustum defined by a perspective camera and the hither and yon clipping planes. Compare viewing box.

view hints objectAn object in a metafile that gives hints about how to render a scene.

view idle methodA callback routine that is called during lengthy rendering operations. Compare file idle method.

view information structureA data structure that contains information about
a view. Defined by the TQ3ViewInfo
data type.

viewing directionThe direction of a view's camera. Also called the camera vector or the viewing vector.

viewing vectorSee viewing direction.

view mapping matrixA matrix maintained by QuickDraw3D that transforms the viewing frustum into a standard rectangular solid. The world-to-
frustum transform is the product of the transforms specified by the view orientation matrix and the view mapping matrix. Compare view orientation matrix.

view objectA type of QuickDraw3D object used to collect state information
that controls the appearance and position
of objects at the time of rendering. A
view object is an instance of the TQ3ViewObject class.

view orientation matrixA matrix maintained by QuickDraw3D that rotates and translates a view's camera so that it is pointing down the negative z axis. The world-to-frustum transform is the product of the transforms specified by the view orientation matrix and the view mapping matrix. Compare view mapping matrix.

view planeThe plane onto which a model is projected. Also called the projection plane.

view plane cameraA type of perspective camera defined in terms of an arbitrary view plane.

view plane camera data structureA data structure that contains basic information about a view plane camera. Defined by the TQ3ViewPlaneCameraData data type.

view plane coordinate systemThe two-dimensional coordinate system whose origin is the point at which the viewing direction intersects the view plane and whose positive y axis is parallel to the camera's up vector.

view portSee camera view port.

view spaceSee camera coordinate system.

view status valueA value returned by
the Q3View_EndRendering function that indicates whether the renderer has finished processing the model.

view volumeThe part of world space that is projected onto the view plane during rendering. See also view box, view frustum.

virtualSee synthetic.

virtual cameraSee camera object.

visual line determinationSee hidden line removal.

visual surface determinationSee hidden surface removal.

warningA condition that, though less severe than an error, might cause an error
if your application continues execution without handling the warning. See also error, notice.

widgetAn element of an application's 3D user interface.

window coordinate systemThe coordinate system defined by a window. Also called the screen coordinate system or the draw context coordinate system. Compare camera coordinate system, local coordinate system, world coordinate system.

window pickingSee screen-space picking.

window-point pick data structureA data structure that contains information about a window-point pick object. Defined by the TQ3WindowPointPickData data type.

window-point pick objectA pick object that tests for closeness between a point in a window and the screen projections of the objects in the model.

window-rectangle pick data structureA data structure that contains information about a window-rectangle pick object. Defined by the TQ3WindowRectPickData data type.

window-rectangle pick objectA pick object that tests for closeness between a rectangle in a window and the screen projections of the objects in the model.

window spaceSee window coordinate system.

wireframe rendererA renderer that creates line drawings of models. See also interactive renderer.

world coordinate systemThe coordinate system that defines the locations of all geometric objects as they exist at rendering or picking time, with all applicable transforms acting on them. Also called the global coordinate system or the application coordinate system. Compare camera coordinate system, local coordinate system, window coordinate system.

world spaceSee world coordinate system.

world-space subdivisionA method of subdividing smooth curves and surfaces according to which the renderer subdivides a curve (or surface) into polylines (or polygons) whose sides have a world-space length that is at most as large as a given value. Compare constant subdivision, screen-space subdivision.

world-to-frustum transformA transform that defines the relationship between the world coordinate system and the frustum coordinate system. Compare frustum-
to-window transform
, local-to-
world transform
.

wrapFor a shader effect, to replicate the entire effect across the mapped area. Compare clamp.

writing loopA section of code in which all writing takes place. A writing loop begins with a call to the Q3View_StartWriting routine and should end when a call to Q3View_EndWriting returns some value other than kQ3ViewStatusRetraverse. A writing
loop is a type of submitting loop. See
also bounding loop, picking loop, rendering loop.

x axisIn Cartesian coordinates, the horizontal axis.

y axisIn Cartesian coordinates, the vertical axis.

yon planeThe clipping plane farthest away from the camera.

z axisIn Cartesian coordinates, the axis that represents depth.

zoom buttonA button in the controller strip of a viewer object that, when clicked, puts the cursor into zooming mode. Subsequent dragging up or down in the picture area causes the camera's field of view to increase or decrease. Compare camera angle button, distance button, move button, rotate button.


3D Graphics Programming with QuickDraw 3D - 18 OCT 1995

© Apple Computer, Inc.

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