Author Topic: Unable to get reasonable results exporting from Blender with mirror modifier  (Read 672 times)

A while back, I thought I understood this problem, and discussed it here:

However, I clearly still don't understand what's going on, and it seems like such a simple thing. All I'm trying to do is paint a model exported from Blender, which has a Mirror Modifier on it. The result is that the model comes into Substance Painter mostly correctly, except that there are very visible seams along the mirror lines. I'd mostly like to know if it's truly possible to export a model from Blender with a Mirror Model on it, and have it look correct in Substance Painter.

The simplest example I can think of is a cube, which I cut in half, and then mirror in Blender:

It's UV unwrapped:

However, this is the result when I bring it into Substance Painter:

The seam line between the two halves is clearly visible.

The point of using a Mirror Modifier in Blender is to avoid duplicating work, and to keep the texture density high. If I apply the modifier, and then unwrap the model again, I can get rid of the seam, but then I've lost the ability to mirror the object, and the texture won't be mirrored.

Does anyone else use Blender, mirror an object, and then paint it in SP? I've tried several things so far, none of which has helped:
  • Offsetting the UVs by 1 unit
  • Flipping the UVs
  • Applying the Mirror Modifier manually before exporting. In that case, it's identical to letting the FBX Export apply modifiers on export.
  • Removing doubles, making sure nothing is marked sharp, making sure everything is marked sharp, nothing changes.