Bump mapping problem

Ladies and gentlemen, there are strange spots on the concave and convex of my model. I confirm that my 2D texture is a problem every month. Please help me to see what is abnormal. thank you。


Seems like they are not caused by the texture itself. You can drag and drop it for example here - and it looks like it’s working just fine, without any artefacts.

Could you share a live example / codepen replicating the issue?

scene.json (46.3 KB)

Thank you for your reply.
If I use PNG, there’s no problem. If I use JPG, this kind of problem will appear

JPG uses a lossy compression - it approximates the colours using a magical combination of sine and cosine functions iirc. This makes images significantly smaller, but also introduces tiny colour changes (the higher the compression, the lower the file size and more colour artefacts):


If you want a pixel-perfect sharp edges, PNG is probably the best way to go.

You should avoid the usage of JPEG for non-color textures like bump or normal maps since the respective lossy compression leads to artifacts. Always use PNG or WebP for best quality.