Need help removing a grey line on my mesh

Support Particles and Physics Simulations
1

I’m trying to animate my dog and for some reason there’s is a grey line that keeps popping up. I don’t know what it is and it seems to be only popping up on hair particles. I’ve attached a short clip of it and also the fur material that I’m using.

MissyFurMaterial
MissyFurMaterial1694×1340 121 KB

NebulaMissyVid0373-0500.mkv (3.9 MB)
Nebula File

2

I’ve got a few things to throw your way, and maybe something will stick.

  • The first is, if you are using Cycles, use the Principled Hair BSDF instead of the Principled BSDF. Don’t try it on Eevee as it isn’t supported.
  • If you are using Eevee, my money is on it being related to your Specular and IOR settings. Most of the time, I leave Specular at the default .5, and if you aren’t making a transparent/translucent material, you should keep the IOR at the default 1.450.
  • I assume the artifact is related to the location of the light in your scene, too. Have you tried moving it?

Give those things a try, and if you don’t have any success, try uploading your .blend and I’ll take a look!

3

@Hunkadoodle Ok so I’ve tried everything you said and it still doesn’t seem to remove that gray line. I’ve put a link to the blend file under the video.

  • The main frames I see the gray line is at frame 76-96 and it’s more noticeable at frame 375-500.
  • I’ve tried moving the whole mesh but I seem to lose the Nebula background design If I try mirror it or rotate it with the entire scene.
  • The nebula design that I’ve created was purely random so I can’t replicate if I move it or mirror it away from the center.
  • I’m also rendering this on Eevee since cycles tends to darken my whole scenery.
  • There’s one more thing If you have a chance to look at is her helmet visor I’m using.
  • The visor tends to fog up her eyes when I render it and I lose that realistic details that I’ve created for her eyes. If there’s any way to get her details to pop out like it does in the material preview I would greatly appreciate if you can look that over too.

I know I’m asking for a lot lol, I’ve spent like 2 months to make this and I really want to make it look as best as it can. If there’s any other recommendations I would greatly consider trying out.

4

So, this seems to be a limitation of the Specular BSDF shader with Eevee and the strand renderer. I can’t say if it is a known issue, but as you can tell, I get the same on both 3.0 Alpha and 2.93.1:

Screen Shot 2021-08-12 at 10.09.41 AM
Screen Shot 2021-08-12 at 10.09.41 AM1920×1170 156 KB

When I switch to Strip rendering for hair, it goes away:

Screen Shot 2021-08-12 at 10.09.49 AM
Screen Shot 2021-08-12 at 10.09.49 AM1920×1170 154 KB

That might be you quickest fix for the hair.

Regarding the eyes, there is a limitation to Eevee that only one level of refraction is correctly modeled:
https://docs.blender.org/manual/en/latest/render/eevee/limitations.html#screen-space-refraction

You may have to switch approaches in order to get the eyes the way you want them. I hope this helps!

5

@Hunkadoodle Thank you so much, I’m happy just able to fix something out of this render. I’ll see what I can do about the refraction of the helmet or the eyes.