Messing with UVs almost always does ruin mipmaps because they are automatically generated by looking at the difference in UV space. These effects interfere with the shaders ability to rely on the standard calculation. You’ll need to explicitly derive the mips.
Change the texture samples mip mode to allow it to be manually derived. Use an unmodified Texture Coordinate and feed it into DDX and DDY nodes, and those into the DDX and DDY slot of the texture sample. This will force it to generate mips based on an unaltered coordinate instead of the modified UVs.
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