In PRMan one can use an optional parameter to raytracing RSL functions:
This then limits the scope of the raytrace only to those meshes in the RIB that belong to the specified set. This is a huge benefit in that it is a simple workflow for optimizing render times by limiting raytracing to only the meshes that absolutely need to be traced.
The RenderMan Artist Tools documentation descripes this parameter thusly:
> "Specifies which objects to consider
> in the trace. When no value is
> provided, the trace set defaults to
> the value specified in the RIB stream
> via the 'tracesubset' grouping
**Does Pixie support this or a similar parameter?**
If not, I suppose I can get clever with my RSL, but I find the subset workflow much more flexible and preferable, and would highly recommend it for future releases.
How have others addressed this issue in Pixie?
Unfortunately Pixie does not support this yet, but it is a good idea to have it in the next release.