Sitting in the Shade with Maya... mia_material shadow shading.
Hello guys and gals.
Just a quick heads-up.
It's come to my attention that there is a performance issue with the "segment" shadow mode and the mia_material shadow shader. It's fine for transparent objects (i.e. it does the job it's "supposed to do").
However, for opaque objects, it is actually doing a bunch of unnecessary work, especially in "Segment" shadow mode - which is the default mode in Maya.
The workaround is very simple; don't use the shadow shader for opaque objects.
Normally, you would use the same instance of mia_material in your surface, shadow and photon slots. Well, if your material is opaque, simply don't put it in the shadow slot. This could gain you some performance.
(In Max this isn't an issue, since first of all, "segment" shadow mode isn't the default, and secondly, the UI frontend actually does the above already, i.e. it doesn't assign the shadow shader at all to opaque objects.)