Maya Faces Black or Inside Out
Dark or invisible faces from reversed normals
Also known as: Maya reverse normals · Maya black faces · Maya conform normals · Maya inside out mesh · Maya face normals display · Maya faces invisible
Quick answer
Faces look black or inside out in Maya when their normals point the wrong way. Select the mesh and use Mesh Display > Reverse to flip them, or Mesh Display > Conform to make the normals consistent, and turn on Display > Polygons > Face Normals to see which way they point. If some faces disappear, check Shading > Backface Culling, because culling hides faces that point away from the camera.
How to fix it
Normals commonly reverse after mirroring with a negative scale, so freeze transformations and then check them. Look at the normals with the Face Normals display, then reverse only the wrong faces, or conform the whole mesh when it is mostly wrong. Check the result in the target engine as well, since an engine can cull faces differently from the Maya viewport. Delete history afterwards.
