I’m a designer so I have no idea why this is happening.
Surly something to do with the minFilter and magFilter. As you are the designer, those are surly where you have placed the seem marks, but why did you end up using textures? Using materials will surly work (unless there is a real reason not to).
Also, sometimes those artifacts appear just because textures are way too small, or if the modifier get applied automatically when exporting to glb. Without the model in hand, I can’t really tell exactly what is happening.
Have you tried loading it on the three.js online editor? Do you get the same result?
How much bleeding? Depending on the texture size + magnification.. you might need a bleed/margin of up to 16 pixels to really nail it.
Or as @MKebsi you could try setting minFilter to nearest.
we are using a character that will give the player chance of choosing the uniform among 50 of them, so I had to use texture for that because there will be about 50 to choose in the game.
If I load it on the threejs editor, it works, but I have to flip the texture manually, whereas the model that my devs are using I didn’t need to do that. Flipping fixed aside, the texture displays properly on my threejs editor testing.
What are the possible things that I may suggest them? minFilter and magFilter?
If it works well on three.js editor (put Y-flipping aside, it is just a toggle), then the code has something! I can’t really tell, but surly they have a process they did to all textures and ended up with this one showing these lines.
The problem is not in your design, and not how you exported it. There is something else with the setting the developer have set that is not clear to us.
Tell them to set texture.minFilter = THREE.NearestFilter.
The other option is not to set UV coordinates on texture edges in the model.
