Static Mesh Specular Highlight Problems, But Normals Seem Fine

Sword of Apollo · Mar 2012

[EDIT: This problem has been solved by importing using binary .FBX rather than .ASE.]

I made a fairly large and complex static model in 3ds Max with two materials and imported it into UDK. (I used a lot of Booleans, and used mirroring to symmetrize the model.) I don't see any problem with the model in 3ds Max, but when I look at it in UDK, it has some places where the specular highlights don't look right. It is as though the normals have a problem, but whenever I look at the normals in either 3ds Max or UDK, I don't recognize any problems. The model has no normal map applied. I have checked the smoothing groups in 3ds Max; I'm pretty sure all polys have them, and all of them appear to be assigned appropriately. I have checked for double faces, double edges, double points and micro-faces. I have checked the polygon normals in 3ds Max, and none seem to be tweaked or inverted. Is it possible that this could be a UV mapping issue? If anyone could give me any clues to what's wrong, I would much appreciate it.

Here's one area with the problem. I am mainly concerned with the issue on the dark rim, but the facets on the tube aren't too hot either:

Here are the UDK normals (green), binormals (blue) and tangents (red) for that area.

Here is the geometry in 3ds Max (realistic lighting):

Thank you in advance for any help.

Vailias · Mar 2012

Notice that you have more than one binormal for a number of those problem areas. It means that you have a vertex split there. (aka a different smoothing group.) try clearing then reseting your smoothing groups in max, either via an autosmooth or just set it all to smoothing group 1.

Sword of Apollo · Mar 2012

Thanks, Vailias, but the problem doesn't appear to have anything to do with smoothing groups. I tried reseting the smoothing groups, using autosmooth, and even removing all smoothing, then importing, and the problem still shows up. I also tried converting the Max model to triangles, and that didn't get rid of the problem either.

Just to be clear, the material I'm using has no normal map. Right now, I'm working on a proper lightmap uv channel, and I'll see if that helps. (I'm new to modeling for UDK, so I initially wasn't aware that this was needed.)

Goeddy · Mar 2012

the lightmapping has nothing to do with specular, unless you bake the spec in (what you should never do).
the problem here clearly are the normals.
first check your mesh for open edges and overlapping vertecies via X-view.
then apply the edit normals modifier, select all normals, and click "reset to default".
if the problem still shows up just rebuild the mesh, it realy is not that complex...

Sword of Apollo · Mar 2012

Thanks for the responses, but I finally found the problem: I was importing the model into UDK using the ASCII (.ASE) format as a certain YouTube tutorial recommended. When, instead, I imported using binary FBX, the problem disappeared.

So I guess the lesson for me here is: Don't import models using .ASE.

Static Mesh Specular Highlight Problems, But Normals Seem Fine

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