NAME

DoPrimSurf − Create a primitive surface primitive object

SYNOPSIS

C:

DtObject DoPrimSurf(surfacetype)
DtSurface surfacetype;

FORTRAN:

INTEGER∗4 DOPMS(SRFTYP)
INTEGER∗4 SRFTYP

DESCRIPTION

DoPrimSurf creates a primitive surface primitive object.  A primitive surface is the outer skin of a classic volume like a sphere, box, or cylinder. 

The primitive surfaces are always defined in a standard local position with a particular orientation.  The user can change their form by applying geometric transformations. 

The parameter surfacetype specifies the type of primitive surface.  Possible values are:

DcSphere <DCSPHR>
Sphere centered at the origin with a radius of 1.0.

DcCylinder <DCCYL>
Cylinder capped at both ends with flat circular plates in the XY-plane and a radius of 1.0.  The cylinder is 1.0 unit deep and extends in the positive Z-direction.

DcBox <DCBOX>
Box with front face in the XY-plane. Its bottom left corner is at the origin and it extends 1.0 unit in the positive X-, Y-, and Z-directions.

DcCone <DCCONE>
Cone with the base circular plate in the XY-plane and a radius of 1.0. The apex of the cone extends 1.0 unit in the positive Z-direction.

With some renderers, a primitive surface is decomposed into smaller elements, such as triangles, before it is rendered.  The amount of decomposition performed is determined by the DoSubDivSpec <DOSDS> attribute. 

When an object defines a closed surface or is oriented such that parts of it face away from the viewer, backface culling will speed up the rendering time. 

ERRORS

DoPrimSurf will fail if an invalid primitive surface type is specified. 

[WARNING - value out of range]

SEE ALSO

DoBackfaceCullSwitch(3D), DoBackfaceCullable(3D), DoCompTextureUVSwitch(3D), DoPatch(3D), DoSphereList(3D), DoSubDivSpec(3D), DoTorus(3D)

September 02, 1992