Unify Normals... Not acting Normal?

[MegaPixel]

The help files for 3DS MAx say that "Unify Normals" is supposed to redirect all normals to face in the same direction (outward or inward). Ok then why does the Normal Modifier or Edit normal mode in subobject NOT do what it says it does?

 

I have tons of archived models in 3ds format that for some reason, have their faces flipped all over the place (saved from earlier versions of max) and it will take me forever to clean them up. Not even does the Double sided texture work on them?

 

Options?

 

-Mega

[Paulo Kiefe]

Please check that all vertices are welded together. The normal modifier needs to have a mesh with all vertices welded.

[Tim Fairbanks]

Mega,

 

I recall (vaguely) a post by Gary Yost on the old 3d Studio (DOS) Compuserve forum in which he explained that the Unify Normals command basically "unifies" the normals of an object by turning all the triangular faces one direction - i.e. clockwise/counter-clockwise.

 

The Unify Normals function is basically stupid; it has no comprehension of what is "inside" or "outside", it simply looks at the XYZ coords of each triangular face and flips it according to the vertex number assignments of each corner of each triangle. It doesn't analyze the whole object.

 

You and I both know that when you create a mesh object that looks like an apple when you render it, it has an inside and an outside. The software has NO comprehension of what an apple IS, much less which side is inside or outside. It just looks at the mathematical local coordinates of each vertex and reverses/flips it, or leaves it alone.

 

Lightscape has a function that flips face normals based on picking a point in 3d space (e.g. the center of a box), but that's a different software package, and max doesn't have that functionality.

 

Unfortunately, I think you're stuck with having to flip the normals manually or using a 2-sided material to render them.

 

timf