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. 

Primitive surfaces are always defined in a standard local 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 of the object’s local coordinate system with a radius of 1.0.

DcCylinder <DCCYL>
Cylinder with front flat circular plate in the XY-plane of the object’s local coordinate system 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 of the object’s local coordinate system.  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 of the object’s local coordinate system and a radius of 1.0. The apex of the cone extends 1.0 unit in the positive Z-direction.

For some rendering states, a primitive surface is decomposed into 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), DoSubDivSpec(3D)

September 29, 2021