Secondary Rays Bias and shadows...

V-Ray for 3ds Max V-Ray for 3ds Max :: General
1

Hi People…

I have few questions… I found use of Secondary Rays Bias parameter very useful - it gets rid of blotches on some parts of model that has very small faces (e.g. windows)… however with this parameter on, i have shadow leaking problem (shadow offset from origin).

Now I have to choose whether I want to have exact shadows or image without blotches… but (suprprise!) i want to have both :smile:

Is there a way to solve this problem?

Thanks in forward

Sinisa

2

This has been corrected for the next VRay release, but in the current one, there is no good solution other than to move the light closer to the scene.

Best regards,
Vlado

3

or render shadow pass separatly

4

or render shadow pass separatly

I’ve never used that before…is there an option for separate shadow pass or i have to do it manualy with matte objects?

Thanks

Sinisa

5

make a separate save of your original scene, put vray mtl wrapper with max mat inside into global material override. In vray mtl wrapper check matte on, affect alpha on, put alpha contribution -1 that will render only shadows and nothing else. Then render your scene with no shadows and comp them together.

6

Not sure if this is the same issue you have but perhaps it will help.

We have the same problem with co-planar faces, using the same solution I found I had to set my spinner snap to 4 decimals then set the value to .0001 so I get my shadows back on my small objects.

7

Would it not be easier to render out the shadow pass through the Vray frame buffer?

8

Do you also need to check “Shadows” in the VRayMtlWrapper parameters to get it to work?