Render with UV coordinates produces strange artifacts

Blender's renderer and external renderer export

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Render with UV coordinates produces strange artifacts

Post by Zoodinger »

Hello all,

I have a weird issue with blender and UV textures. I created a model from scratch and assigned UV textures to it. So far so good.

However, whenever I render I get these weird pixels at places:

I realized that these pixels have the color of the mesh material, which is yellow. So, I thought, maybe some vertices are either uncovered or they have transparency. I tried painting over the texture in photoshop to make sure, but I STILL had that problem.

Then, I used a non-transparent png (as I don't really need transparency in the first place) and what happened was that those pixels got the color of the background of the .png (red for demonstrative purposes):

Note that the background appears only at non-mapped areas of the texture. The colors bleed out of the UV faces quite a bit, so it's not a border issue. I even tried painting over that area with the Texture Paint tool, with no luck at all

It would seem that some vertices are mapped incorrectly, but checking the UV arrangement they don't appear to be. The same thing happens at a different area on my model. Furthermore, the model in the 3d viewer appears correctly. Creating a new mesh doesn't solve the problem either.

A simple workaround would be to set the background color of the texture to black. That way when artifacts appear they won't be noticable. But I'd like something better than that, and I wouldn't want to come across the same issue later in which this solution does not look good. Any ideas what might have caused this? Are there any weird vertex-specific settings that I might have altered by accident?

Thank you in advance.

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