The RenderMan Interface - Paul Bourke

RiSolidBegin( RtToken operation )
RiSolidEnd ()
SolidBegin the definition of a solid. operation may be one of the following tokens:
”primitive”, ”intersection”, ”union”, ”difference”. Intersection and union operations
form the set intersection and union of the specified solids. Difference operations
require at least 2 parameter solids and subtract the last n-1 solids from the first
(where n is the number of parameter solids).
When the innermost solid block is a ”primitive” block, no other RiSolidBegin calls
are legal. When the innermost solid block uses any other operation, no geometric
primitives are legal.
RiSolidEnd terminates the definition of the solid.
RIB BINDING
SolidBegin operation
SolidEnd -
EXAMPLE
SolidBegin ”union”
SEE ALSO
RiInterior, RiTrimCurve
A single solid sphere can be created using
SolidBegin ( ”primitive” );
RiSphere ( 1.0, -1.0, 1.0, 360.0, RI NULL);
RiSolidEnd ();
Note that if the same sphere is defined outside of a RiSolidBegin-RiSolidEnd block, it is
not treated as a volume-containing solid. A solid hemisphere can be created with
SolidBegin ( ”primitive” );
RiSphere ( 1.0, 0.0, 1.0, 360.0, RI NULL);
RiDisk ( 0.0, 1.0, -360.0, RI NULL);
RiSolidEnd ();
(Note that the -360 causes the surface normal of the disk to point towards negative z.)
A composite solid is one formed using spatial set operations. The allowed set operations
are ”intersection”, ”union”, and ”difference”. A spatial set operation has n operands, each of
which is either a primitive solid defined using SolidBegin (”primitive”)-RiSolidEnd, or a
composite solid that is the result of another set operation. For example, a closed cylinder
would be subtracted from a sphere as follows:
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