Only some UV faces Inverted in 3DS Max??
polycounter lvl 6
Hey guys, I did a check for Inverted UVs in 3ds and I flipped all the ones that were completely inverted but I noticed some of the faces within the same UV shell were also flipped? Why is this and how do I fix this? Could this be a problem if I have text running along the same shell? The faces in red are what show up when I check for inverted polygons in the UV Editor. Any help would be much appreciated.
Replies
yep, uv faces will match the orientation of its mesh face. colloquially the front is called its normal and the opposite its backface. we want to "normalize" the faces on a mesh, so their faces are correctly oriented, before unwrapping. geometry and uvs are stored within their own coordinate system independent from one another. x,y,z being the geometry's space and u,v,w being the surface's projection space. were you to change one, flip one facing, it would reverse the texture cast onto the mesh's face.
One thing that's worth mentioning is that max's inverted faces view can be misleading
The shape of faces in the W coordinate can cause false positives, as can "almost" overlapping edges.
check W - if it's flat, comfirm that the faces are actually inverted - its very unlikely that a face that's welded to another will be inverted if the other is not (impossible if it's an editable poly)
Simply having n-gons will sometimes cause max to think theres an inversion as well, since the uv polygon has more than 4 vertices.
Thanks so much guys. Really appreciate it.