Is there a cure for cutoff problems?

[timmatron]

Low value in cutoff of light (.001) gives me really harsh lines in reflections of this dark material. If I move it up to say .01 I lose the reflection entirely. Everything in between presents problems once place or another at these glancing angles. Is there any solution? I tried cutoff both in the material and light but I can't get a good clean render out of it.


EDIT: I saw Vlado's suggestion of setting it to zero. I think that might work, I just hope it doesn't jack my already high render times.

EDIT II: Yes, it did indeed jack up render times, probably by 2-3x. So if there's a better way than 0 cutoff that I'd still like to know.

[Deflaminis]

Is Dim distance not an option? It even has a falloff parameter... I think cutoff and dim are basically similar/same? At least, they are as described by the help.

[timmatron]

"Cutoff – this is a threshold below which reflections/refractions will not be traced. V-Ray tries to estimate the contribution of reflections/refractions to the image, and if it is below this threshold, these effects are not computed. Do not set this to 0.0 as it may cause excessively long render times in some cases."

I'm not really sure what the "threshold" refers to. My thought, based on this experience is that it is related to angles, whereas the dim distance is, well, distance related if you want to fade out reflections at a certain point from the camera.

[Deflaminis]

If it was related to angle of incidence why would your reflections disappear entirely at all angles? Interested to see the solution.

[timmatron]

No idea! I ended up just selecting those few lights that were the problem and setting the cutoff on those to 0. Render times were still really high but I got through it.