I have encoutered problem when working with vray passes. In some of my scenes appears very sharp black noise in Global Illumination pass that is more or less noticeable in raw render.
No matter of the basic render settings (DMC noise treshold, resolution etc.), once it appears, the noise is present every time.
Areas affected are usually those with some dark material/texture.
scene setup viz printscreen:
3Ds Max 2013 + Vray 2.30.01
Gamma 1,6 or 2,2
No extremly complicated geomery.
No some extra special vray materials.
No other mental ray, a&d materials (I hope so)
Basic lightning: Sun + vraysky + few vray lights
No matter if using Vray frame buffer od not.
I did try by trial and error various scene setups including using global override material, check/uncheck filter maps, reset of the lightning in scene (delete old, create exact same new), import geometry in blank scene, no reflection/refraction etc... It made sometimes black noise disappear... usually that last only until few renders later or save/load current scene. Never managed to ged rid of it permanently.
Could it be some corrupted texture? (using usually RGB *.jpg... sometimes in resolution >12000x12000px (flooring))
Second question is about basic glass material... sometimes in GI pass it appears pure black and sometimes appears as any other solid geomery (blue arrows).