Seams on Curved surfaces./ Properly Scaled Uvs
polycounter lvl 6
So my partner and I are working on an Unreal scene together. He models and unwraps and I texture. On this particular model the UVs aren't properly scaled and there are way too many seams. When I brought this up to him he says:
That's a common problem with very curved surfaces like the couch. There is no way to weld the uvs because it will severely stretch the texture. But that's why we have substance painter. The pattern won't work well with substance painter though. A really firm normal black leather would have probably been a better route to go in so the seams could be painted over. Basically there's no "fixing" the uvs on the couch. Painting over them is the solution imo.
Is he correct? Please help me. I don't want my textures looking like the mess they currently look like. He can't be rightbecause I've seen way more complex couches here on Polycount where there weren't any seams showing. As an example:
Replies
Also the way these uv's are layed out is not really optimal, you should always try to avoid the really small uv islands because these probably wont be bigger then 1 or 2 pixels and it is impossible to texture that way.
I think the way this model is unwrapped shows your friend has some experience in UV editing but does not know exactly what he is doing , I suggest having another look at the unwrap or for an easier solution use a tiling pattern for the holes and use the UV map modifier in max instead of the UVW unwrap.
Hope this helps and good luck
Would you know any references that might be good for him to look into?
Also how you need to handle seams depends on if you are using tiling textures, or if you are able to bake a high poly model. That chair you posted is obviously baked down from a high poly model, and if it's done correctly, you can easily hide any seams. You don't have that luxury if you are texturing by hand or using tiling textures.
Generally, more uv seams means less distortion, that is correct, but I'm not sure that really applies to the mesh in question. Its hard to say without seeing the mesh myself.
Also, while you do need a uv split everywhere you use hard edges, the reverse is not true. It can sometimes be beneficial to do so, but this couch has some softer shapes that would not benefit from many different smoothing groups. If you're not baking a normal map from a high poly source, this is essentially moot as well. This isn't really something you come back and do later, so if you're going to do it, create the highpoly now and go full force. You can do it later, but its not really typical and would be a waste of time, plus the lowpoly mesh's construction usually has a lot to do with how the highpoly is built.
Also, its a bit weird having you relay his comments, he should probably just post himself.
If you want to post an OBJ of the original chair mesh, I (or someone else) could probably post some alternative uv layouts.
Lots of your long thin islands are slightly crooked which could cause problems compared to perfectly straight UV borders.
Depending on what this prop will be used for, you could mirror the cushions so they occupy the same UV area which would free up a considerable amount of space, but it would be sacrificing the ability to apply any obvious unique marks on your texture map like tears, stains, missing buttons, etc.
On an unrelated note, the polygon density of this mesh is very high for what it is, especially considering many of your surfaces are totally flat, like the cushions, frame, etc. The model itself could stand to be optimized which would make UV mapping easier and faster.
The couch cushions and the other parts of the couch made of leather have equal texel density throughout. I thought it would be better to maintain that even texel density of the cushions and back rest of the couch rather than resizing the cushions and not being able to resize the back rest. Should I go back and fix it?
Then I had the dilemma of either splitting the uv's of the couch backing to uniformly scale up the cushions and backing or leaving them with little total uv space. I chose to leave them with less total uv space and to fill that space I increased the frames size. Is this the right way to go about it?
If there are better ways of handling the split uv's/give uv's less space dilemma I am urgently looking to learn more about it.
Regarding your advice Bartelon, you're right. I should have optimized the mesh if not to just making the uv'ing easier on myself. It's for architecture visualization so I went a little high on the polycount. Really unnecessarily high in my opinion. I really want to make this the best prop that I can. How important is optimization for visualizations?
Thank you all for your help.