Light Cache + VrayLightMtl + Back face + Shadow/Light Falloff + Opacity Map

[RotemS]

Sorry for the long winded title.

This particular esoteric combination causes the light cache to hang indefinitely.

Attached is a snippet which recreates the issue.

delete objects
renderers.current = vray gi_on:on gi_primary_type:3 gi_secondary_type:3
t = teapot()
addModifier t (normalModifier flip:on)
t.material = vrayLightMtl texmap:(falloff type:3) opacity_texmap:(gradient_ramp())
max quick render

Using 3dsmax 2014 with VRay 3.20.02 build #25882.

[tashko.zashev]

Hi,

The infinite LC calculations was reproduced in our render tests here and the case is now logged in our bug tracking system.
The culprit seems to be the Falloff map set to Shadow/Light.

Thank you very much for this report.