Triangulated shadows

Here is a sample, with buffer and ray shadows. There are regions with correct shadowing and regions with triangulated shadows.
It seems the problem is in the mesh. That is a duplicaded of an skinned one, with SubSurf and smooth.
Material has OnlyShadows marked and A = 1, since it is for matting.
Can be vertex groups the reason perhaps?

So the top (green) pic is the onlyshadow one. But which of the 2 are the duplicate? For the top-left one in the green pic, are you sure you don’t have motionblur on?

For the bottom (blue) pic how many shadow samples and what’s the bias?
Check this recent thread:


Yeah, it was a problem with Bias value. I used lowest value in maya and I continued so that with blender. With 0.1 value those artifacts have gone out.
The left green is the used in blue image, the right one is using ray shadows to see there was a problem with both methods. There is not motion blur.
It is solved (or patched) with buffer shadows, wich I use.
I have been told SubSurf can be the cause of such artifacts, is that right?

I haven’t heard that.


I found the problem.
Blurred effect was caused by Bias parameter.
Triangulation was caused by a Hemi light in scene.

Triangulation was caused by a Hemi light in scene.

Thank you for pointing that one out.


Not at all, that’s for a forum :smiley:

NOTE: I have been updating the render in the first post, so nowadays there are not arfifacts.