What causes this Render flaw?

lexbaird

I've gotten similar artifacts from time to time, and would like to know what causes it.

The light set up: 3-delight with 3 distant lights (key, fill, rim) and 1 spot. Spot set to "no shadows". Shadow Bias: 1.00

Render settings: Progressive; Bucket: 8, spiral; Max raytrace depth: 1; Shadow Samples: 32; Shading Rate: 0.20; 1236px x 2000px

Note that when rendered from a different camera angle, the artifact disappears. The flaw does not appear to follow the mesh geometry (G3F)

scorpio

Try lowering your shadow bias

alken

This happens to me when depth of field is turned on and i'm test rendering.  Once I do the real render those anomalities go away. Hope this makes sense.

lexbaird

Alken, this is happening in my final render (actually, this is a spot render of the same flaw after I tried a few different settings, but it was showing in the final render.)

Scorpio: I'll give it a try, but as I understand it, shadow bias flaws are caused by self-shadowing and look like the underlaying mesh. I dunno what would be casting on itself in that area. Is there a recommended setting? 1.00 is the default, and one try at it was set to .50.