Author Topic: Texture streching with subdivison in Blender  (Read 1593 times)

Hello! I´ve export one model from Blender to Substance Painter in Fbx format, bake the texture maps,etc., and all is ok.
My problem come when apply the painted textures in Blender with the Subdivision modifier. Seems like the modifier displace the seams streching the texture in this zone.
I´ve tried a lot of things to fix but there is no way.
Can someone give me some advice or what can I do?
Thanks in advance.

The problem is not that your textures are stretched but that your geo is. Your textures have been made to fit on a mesh that was not subdivided, so there is a discrepancy in coverage. Subdivide your mesh before going into Painter to avoid this sort of issue.

Is there anyway to work in the low poly mesh (baking the texture from the high poly) without this problem?

Last Edit: August 15, 2019, 01:15:59 pm

This problem will often happen with (too) low poly meshes that need to be converted to a subdivision surface afterwards.

How much stretching is visible also depends on the rendering application, it seems that Blender doesn't interpolate well here (I don't think that much stretching would be visible e.g. in Modo). Do the UVs stay linear when you apply the subdivision modifier?

There is little you can do but subdivide the entire mesh, or insert edgeloops locally so the edges do not shift as much when subdivided.

Can you share the mesh?
Last Edit: August 15, 2019, 03:47:19 pm

Finally I found two solutions, derived from your comments ... thanks!
1.- When Blender unfold the mesh, it has an option (by default unchecked), so that the UV's take into account the position of the vertices with respect to the Subdivision modifier.
It works well but the mesh unfolds with more distortion, I guess you have to be careful when retouching it so as not to change the Geo of the vertices.
Increasing the level of subdivision above 2 (usually the value used), no problems appear.
2.- In the mesh I had placed the seams in the "holding" loops to make them less visible and I did not take into account the stretching or displacement of the vertices when subdividing.
Placing the seams on the "control" loops, as they have very close support edges, it barely moves when subdividing and stretching is not appreciated.
I suppose that I must incorporate into my workflow a preview of where I am going to place the seams to adapt the topology also to the UV's, taking into account if the model is going to be subdivided, if I am going to paint the textures, etc.