Can anyone tell me if they recognize this artifact and suggest a possible fix? It always appears on this side of the tree. I have tried a number of different lighting setups, UV unwraps, and recalculating normals.
It’s really bothering me, any help would be very appreciated.
edit: cycles render only. Does not show up in viewport.
Have you checked for correct facing of normals? edit, oh yes recalced. And/or duplicate geometry in the same space.
The darker right hand side of the trunk looks to have very strong normal map effect. The rest little or none.
Yes. I thought about intersecting geometry, the main thing I can think of is the branch, but the same thing happens when I move it away. Also very strange that it appears behind the trunk in the render, the branch is supposed to be going into it.
I also deleted the trunk shape and applied the texture to just a clean, basic cylinder. No luck.
above at normal strength at .2
Increasing normal strength actually helps a bit, but it still looks very weird.
Here is normal strength 9.2:
Try a different texture. That could establish if the problem is geometry related or some issue with one specific texture.
Well that has eliminated one possibility.
You know, I suspect UV unwrap issue. While it should not be complicated and you have looked into it. I can only imagine those vertical straight lines as the result of compressed or somehow bunched up a bit overlapping UV islands. Given the rest is ok.
Images 2&3 show the end of a log or something just poking out of the white area, with the same effect on it, probably. If that is so might knowing it is on two items aid detecting the cause?
show material nodes
Show wireframes
I haven’t worked much with Normal maps but, seems to me that they’re always in shades of blue red and yellow.
Remove the displacement.
I rarely is ever use it. But I believe to work it needs fine detail level of vertexes, faces. You have a very high number going round but they are all very long. That alone might be the problem the system trying to create bump on huge long thin single faces.
There is a ‘rule of thumb’ for texturing faces ideally should be about square.
I would make a tree trunk with a lot less verts in the circle. 32 likely to be plenty. Many go much lower.
Try a fresh tree trunk, less verts and at least some loop cuts up its length.
If it works on that you can decide on making a fresh tree or downscaling the verts on the original.
Yes that will be his diffuse not the normal map. UV mapping will be the same.
Aghhh still there?
Though the UV and trunk look much more usual now.
Save close and reopen? Sometimes removes a glitch.
Hit computer with hammer? lol no do not try that one!
The tie up between those long thin faces and that visual effect seemed the answer.
Yeah, I’ll try the old reboot. Otherwise the solution is probably pivot the camera so it’s not in frame 
Yes or get out a chainsaw!
My point is that Normal maps are color maps and the Normal Node takes in color data
@yo_johann, could you humor me please and try switching your normal texture to sRGB instead of Non-Color?
No luck with the color mode (or the restart).
Ok great news, I’m an idiot at there was an old version hanging out with render on. So, deleting that and applying the texture to a clean cylinder with 32 verts and no loop cuts works.
Great news!
Squaring or not such long faces is good practice though. On the previous loop cut uv, I would scale the tree trunk UV in the Y direction to replicate the proportions of the rectangles making up the tree trunk on the model. Or the texture is stretched in one direction. Box select it in the UV editor, S, Y, drag to shape. Triple the length roughly by the look of it. Assuming a tiled texture, do not worry if going outside the image. It is tiled, it sorts it out. Also you can go over the end circles, it does not care how many uv areas are on top of each otther.
