The RenderMan Interface - Paul Bourke

Opcode Operands Operation
0 count, ... add
1 count, ... multiply
2 count, ... maximum
3 count, ... minimum
4 subtrahend, minuend subtract
5 dividend, divisor divide
6 negand negate
7 idempotentate identity
8-99 reserved
Table 5.3: RiBlobby opcodes for combining fields.
The add, multiply, maximum and minimum operations all take variable numbers of
arguments. The first argument is the number of operands, and the rest are indices of
results computed by previous instructions. The identity operator does nothing useful,
and is only included for the convenience of programs that automatically generate
RenderMan input.
RiBlobby primitives may be shaded much like ordinary parametric primitives, with
the caveat that just like subdivision surfaces, they have no global u and v parameters.
Nevertheless, they may be given vertex values by attaching scalar values or reference
coordinate fields to primitive sub-objects.
RIB BINDING
Blobby nleaf [ floats ] [ strings ] ...parameterlist...
The number of points is determined implicitly by the length of the ”P” array.
EXAMPLE
Blobby 2 [ 1001 0 1003 0 16 0 2 0 1 ]
[1.5 0 0 0 0 1.5 0 0 0 0 1.5 0 0 0 -.1 1 .4 .01 .3 .08] [”flat.zfile”]
5.7 Procedural Primitives
Procedural primitives can be specified as follows:
RiProcedural ( RtPointer data, RtBound bound,
RtProcSubdivFunc subdividefunc, RtProcFreeFunc freefunc )
This defines a procedural primitive. The data parameter is a pointer to an opaque
data structure that defines the primitive. (The rendering program does not “look
inside” data, it simply records it for later use by the procedural primitive.) bound
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