Crazy normals!

zombie420

I have a pretty simple shape I'm working with but the normals are just not cooperating.

1) Turning off "double sided" in Maya reveals that the normals are reversed.

2) Displaying face normals reveals that the normals appear to be facing the correct direction?

3) The cage created is mangled like crazy. I assume that even if I manually fix it, it will give me undesired results.

This is a new problem to me. How do I fix this?

tristamus

Wow, quite a mess. Since it doesn't look like you were too far along as it is, so I'd just start over.

As far as what the problem could be, yes, reversed normals. For the cage? No idea.

Next

export import it as obj. should do the job... as i am no maya pro i dont know what could cause this...

poopipe

Reset/freeze transforms. This usually comes from negative scale as far as i can work out. Whether its user error or maya being a tit i couldn't say but i get a lot of models like this given to me by our maya modellers and end up having to fix them in max.

Bal

Also check in the Attribute Editor, under Render Stats, that the "Opposite" checkbox isn't checked (as poopipe mentions, this happens when you do a negative scale, then freeze the tranforms). If it is, you might to uncheck Double Sided to uncheck it (you can then recheck Double Sided... so silly).

gilesruscoe

looks like the normals ARE facing the wrong way, dispite what maya is showing you with the green normal directions, the faces themselves are in fact facing the wrong way (you have backface culling on and the object appears inside out). Just flip normals, delete the cage and then generate a new cage again. Also deleting history and freezing xforms before making a new cage is always a safer way to do things.

JamesWild

I do wish 3D suites wouldn't talk about surface normals as if they defined the side you can see triangles from (the face winding, CW or CCW) rather than the reality which is surface normals being generated from the face winding via a cross product. Making buttons like flip normals actually flip the face winding obscures what's really going on and leads to a lot of confusion.