How to get rid of these artifacts

[Brian Jones]

have you tried adjusting the Phong Angle in the Phong tag?

[Ryan Paterson]

Ugh I was REALLY hoping that would work but sadly, no. Good tip tho!

[Brian Jones]

got to know more about the scene then. Which renderer, what lights (if any) GI, AO etc. might it be specular rather than reflection we are looking at? what is it reflecting – etc. etc. etc. It’s hard to tell without the scene file.

[Adam Trachtenberg]

Also, where did the model come from? Does it have a normals tag? Can we see a wireframe?

[Ryan Paterson]

Have at it!

7923_skull.c4d.zip

[Brian Murphy]

This may be over simplifying it and you may have tried it already but I get artefacts that look similar when the shadow maps in my lights are not a high enough resolution.

If not that, is your reflection map a high enough resolution – looks like the reflection is pixelated.

Third, have you optimised all points on the model?

[Brian Jones]

I am not seeing the artifacts here *but* I don’t have the lighting kit pro. I do have the hdri kit though so I turned off the lighting kit parts (due to their textures being missing) but I left the area lights on (buried in the light kit parts). No artifacts. I have to guess that the image called Stripes.jpg, that C4D tells me is missing, is responsible for your stripey artifacts, at least with what I am seeing.
BTW this renders _way_ faster in the physical renderer even with the settings turned up a bit to match the standard render (4 sec vs 57 secs here)

[Emir Bojorquez]

As you can see in the first image, that is caused by some shading issues and geometry of your skull in combination with the Subdivision Surface.

To solve this:

1.- Delete the Normal Tag that the Head and Jaw has (the one that looks like chessboard).
2.- Select the Head and the Jaw, then go to polygon Mode and select all the Polygons (Ctrl + A).
3.- Right Click and move the mouse to Untriangle and click over THE GEAR NEXT TO THIS COMMAND.
4.- inside the Untriangle Command Menu increase the Angle to 50.
5.- activate the Phong tag and increase to 60.

Good Luck

Imagination is the best tool…

[Ryan Paterson]

Worked like a charm! Thanks so much. So basically what I just did was simplify the geometry and smooth out the angles? Can I ask what made you realize you needed to un-triangulate? I’m really trying to learn as much about 3D as possible, and it’s always these little technical details that seem to make all the difference.

Really appreciate you taking the time to help, thanks again 🙂

[Emir Bojorquez]

triangles usually produce anomalies when you smooth your models using subdivision Surface, that is because of the uneven amount of vertices, that also happens with N-gons.

Good Luck

Imagination is the best tool…