I found, while texture painting my dog model, that when hand-painting the eye socket, with X mirroring turned on, it wasn’t painting symmetrically. The dog has a distinct black eyelid and when I painted it, one side had a thicker black on it than the other side, especially noticeable when I had the actual eye not hidden. I could paint it without symmetry turned on but to me, it indicated a problem with the model.
Even though I had about a week’s worth of painting time I thought it best to try to correct the base model. So I cut the model in half and then added and applied a mirror modifier to it.
Then, when unwrapping it again I found that the head (I haven’t re-unwrapped the body) UVs had anomalies. When I rotated them and placed them in the center of the first UV space, (I have set up UDIMs), it does not have the same margin space on the left side as on the right side. I set the x location to 0.5 so it is set in the center. See number 1 side is wider than number 2 side.
Then, when enlarging the nose hole you can see the first vertices on either side of the center vertex aren’t mirrored properly. The vertices, starting with the number 2 vertex, are lower than the vertices on the other side of the centerline vertex.
The mesh looks like it has duplicated geometry…in the UV window, you can see the selected ( orange) but there are still Black bars that indicate an Unselected area that shares Vertex location…do a merge by distance and see what happens, also because it is duplicated, then the ( Inside?) will have normals reversed …that will really mess things up, with a single UV. The UV is also stretched quite a bit which will mess with your mapping.
RSEhlers
I looked at it from inside and there is nothing there. I did a merge by distance and increased it to .0009…and it merged almost 200 verts. Then I unwrapped but the same distortion appeared.
I started over. Cut the mesh in half. Merged by distance with the remaining half just to make sure there were no overlapping verts. There was zero.
I mirrored again. Applied the mirror modifier. Checked merge by distance and looked inside the head to see if there was any loose geometry. Everything looked fine. Checked normals and they were all facing correctly. Unwrapped again and still I get the same result.
By the way RSEhlers, what picture are you looking at that shows Black Bars? I don’t see any.
I did an experiment. I changed the Mark Seam loop around the nose. I showed three screengrabs. On one, the distortion appears on the opposite side of the centerline. When I selected a loop closer to the nose the distortion appeared on the right side again but seems a little less distorted. However I noticed that the centerline vertices were not straight but appeared curved near the nose hole. When looking at the other screengrabs the centerline curves also. It curves toward the distorted side.
I am not sure how to solve this other than to rebuild the head from scratch but I dread doing that as I have started this model over three times already.
Can I just manually change the UV polys to make it more symmetrical?
I am not going to use this model for any really close-up shots so it probably won’t make that much of a difference.
Again thank you all for all the help in your replies. I don’t know what I would do if it weren’t for the folks on its forum.
UV distortion can be visually identified through the option.
If it is a model that can be disclosed, it is helpful to attach the .blend file.
※ The attachable capacity is 5mb, and you can attach the capacity above that outside and leave a link.
The model has a multi res modifier and that make the file over 400 megs. I still don’t understand the part about the lower part of the nose should be open but UV is closed.
This model is based on my taking the VFX Grace Animal Creation Course and they recommend giving the nose it’s own separate UDIM space due to the amount of detail they intend to apply to it.
I’m thinking maybe I can make the head a separate object and see if that lowers the megs to 5 or less.
