vector pathtrace(vector P, vector N)
See optional parameters.
pathtrace works like irradiance, but uses the physically based
rendering (PBR) engine to do secondary bounces.
pathtrace provides a simple (and not very flexible) method of invoking the
PBR rendering engine from micro-polygon rendering. It uses path tracing and
F (BSDF) output, not
Of on the hit shaders. Maximum path depth
is controlled by the “diffuse bounces” parameter on the PBR tab of the
mantra output driver.
Irradiance caching works the same way it works with occlusion().