UT3 Normal map seams?

Kupikimijumjum

So I have this using Xoliul's shader in max:



And when I bring it into UT3, none of the uv seams flow correctly.



I baked the model with xnormal, and the entire model is symmetrical.

I tried flipping the green and red channels around, as well as re-baking the normals with increased padding, and from other applications. Nothing seems to work.

Here's the UV layout if it helps.



After asking around at school and spending a few hours tweaking with settings, I'm totally clueless... Any help would be appreciated!

gamedev

All unique UV's, no mirroring? And a strange question, but what does your 2nd UV channel (lightmap channel) look like?

Kupikimijumjum

The uvs are mirrored. Is that what's causing the problem? And the intention was for this fella to be a character, so I didn't think I lightmap channel would be needed.

gamedev

The uvs are mirrored. Is that what's causing the problem? And the intention was for this fella to be a character, so I didn't think I lightmap channel would be needed.

Unreal has some pretty strict guidelines for mirroring if you don't want to see seams. The rule of thumb - mirror only horizontally. You're UV seams will also need to be on a perfect vertical, no curves, just straight lines on the vertical axis.

As for the second UV channel, this only has to do w/ UE3's real preview in the model viewer. Generating a second set of UV's with no overlapping (and again following the same mirroring rules and ensure no faces are inverted) can often fix those realtime viewport seams. Can't explain why, just that it works.

For most characters, I would presume a unique unwrap.

Hope that helps!

crazyfingers

This might help, lots of people seem to have this issue today:

1. Move all your existing UV's up 1 channel
2. Create a new UV channel 1 and do a quick planar map or sphere map that gives you the least seams in the best possible places (UT3 appears to use seams in map channel 1 to determine smoothing groups)
3. Reimport your asset and adjust your mats and light channel accordingly.

Kupikimijumjum

Ok, so I followed the uv channel advice... After struggling with getting my channels to both save and export correctly, I finally got some results. It definitely helps, but am I correct in thinking that no matter which way I layout this junk uv channel I'm going to have some sort of seam?

Also, would these uv channel seams still be an issue if the real uv's aren't symmetrical?

Kupikimijumjum

I just noticed too, it looks like certain parts of my model has the normals flipped... The legs and head are flipped from the body, possibly other clusters too... I don't get it! why am I only getting this issue in unreal?

[HP]

Might help, dunno:
http://boards.polycount.net/showthread.php?t=51088