Here's a render I did based on one of the Scatter/Blinn experiments bb posted at RDNA. It's just James and one infinite light in the scene - I think for this render I actually removed bbs shaders and just had the textures running out of the ordinary diffuse channel. I've adjusted levels in photoshop to clearly show the problem - tiny white dots in the shadows).

The interesting thing here is that I've disabled SSS and removed all specular, displacement and bump (it's just diffuse shading), so they don't seem to be contributing to the tiny white dots in the shadow areas. Only IDL is enabled, and the white dots go away when it's disabled. I've also tried various values for RT shadow bias, blur and samples but none seem to cure the problem. Rotating the light a little can help, but isn't an outright solution.

I have no idea what is causing it, other than it seems related to IDL or raytracing.

 

PoserPro2014(Sr4), Win7 x64, display units set to inches.

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