I’m having some difficulty getting rid of artifacts from a hair emitter. See the image below - there are small dots around the character’s eye (both in the eye, and around the skin.)
I don’t want to render with strands because of the appearance of the shadows. The “adaptive” setting seems to make much nicer shadows but it produces these dots on my final render. If I move the camera, the dots will randomly disappear and others will appear in new places.
I’ve checked and rechecked and there is no way that any of the hair particles are coming back through the inside of the mesh and poking out. When I zoom in on these dots, they disappear!
They are there regardless of SSS being enabled or not. I have tried increasing my samples and sizes for the soft shadows and nothing seems to get rid of these artifacts.
At one point, I deleted the back of the head from the hair emitter and it appeared to clear up a few dots, but not all of them. Is there some sort of alpha problem that’s making strands force to the foreground?
I want to use soft raytraced shadows because the shadow buffer method doesn’t seem to give me the look that I’m going for.
Not 100% sure unless I see the file, but usually I create the hair (scalp) as a separate unit to help prevent those type of artifacts- are they the same model or already separate? Thats perhaps one way to do it- there are probably others…
I’m using Blender 249… any chance that this would be fixed in the new alpha?
Update: No, if anything, its worse in the Alpha (hah!)
Its pretty easy to recreate this issue also. I created a brand new .blend and just put a sphere in front of a cube that has a hair emitter on it. All I did to the cube was enable the hair particles, set length, roughness, combed it, and enabled children. This is the result:
As you can see, the sphere is clearly not touching the particle mesh at all - its nowhere NEAR the mesh! All of the default rendering options are enabled, but on my original scene i found that the hair artifacts still showed up when shadows, SSS, radiosity AND Oversampling were all turned OFF.
This happens regardless of Oversampling / Shadows / SSS / Radiosity enabled or disabled.
This happens only with “children” enabled on the particles.
This only happens with particles that have been “combed” using the comb tool.
If I enabled Abs Length and set the Max Length value to something small, it stops the strands.
It appears to be that the Z-depth of some of the combed/modified particles gets set to a massive number and approaches the camera regardless of stacking other mesh’s in front of the strand.
Is this a known bug, or should I submit a bug report to the developers?
