Texture Shimmering at a Distance
Sparkling or crawling surfaces on far objects
Also known as: Texture flicker distance · Moire pattern game · Shimmering textures · Specular shimmer · Texture aliasing · Normal map shimmering
Quick answer
Textures shimmer at a distance when very fine, high-contrast detail is sampled by too few pixels and the result changes from frame to frame. Make sure mipmaps are generated, set a higher anisotropic filtering level, use temporal anti-aliasing or an upscaler, and reduce high-frequency detail in the textures. Strong normal maps and sharp roughness details are the usual cause of sparkling highlights on distant surfaces.
How to fix it
Look for the surfaces that shimmer, which are often fences, grating, brick patterns, grass and noisy normal maps. Lower the normal map intensity, blur the smallest details, and make roughness less contrasty for far LODs. Use LODs that simplify materials and geometry as they shrink. Check the texture import settings for mipmaps and filter mode, and compare the results with and without anti-aliasing.
