This is very noticeable along texture seams, but it occurs on every edge of this particular UV island. All of this is a single mesh with multiple UV layouts and materials, the head/neck area is a separate UV set from the body/armor/backpack/etc. The head/neck UV island is the only one that experiences this strange aliasing along the edges. I’m using forward shading and MSAA anti-aliasing for my project. No lumen. No nanite. Trying to keep things bare bones and simple. Any info or tips would be greatly appreciated.
Hello there @DannyMacFinn1!
Since this only seems to affect the top of your character’s head, I think the problem comes from that particular island’s textures or material, rather than the geometry. MSAA only smooths the edges of the geometry itself, so it won’t fix any lines that come from the textures or the shading.
This is most likely texture bleeding at the edges of that island. When a texture is seen at a distance, or at a steep angle, the engine uses mipmaps for it, and the pixels get blended together. If the space around your UV island is empty, or filled with a different color, that color bleeds into the edges, and that can result in the line you are seeing.
We just need to isolate the issue. Start by making a copy of the head material, and test the following:
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Replace everything with a simple, flat color, no textures at all. If the lines disappear, the problem is in the textures or material, not the mesh
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Temporary disable mipmaps from your texture (set “Mip Gen Settings” to “NoMipmaps”). If the lines disappear, the mipmaps are bleeding the background in. Check the area around the head’s UV island in the textures. If it’s surrounded by any color that doesn’t match the edge of the island, that’s what’s bleeding in. Re-bake or re-export all the head textures with more padding
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Test by disabling the normal maps, and check if the lines remain visible without them. If not, then it’s the normals. Make sure the normals along that seam are smoothed in Blender (or your 3D tool fo choice), and that the normal map was baked using the same mesh and normals you exported to UE