View Full Version : 3Dsmax to UDK Flipped UVW's Problem
04-20-2010, 05:23 AM
Ive created a model in 3Dsmax 9 and am importing it into UDK (the new one) there is no real problem until i apply the normal map ive created and then i see some bad shading going on where ive flipped my UVW's in max.
here is a picture of the effect;
here is a sample of my UVW's showing that ive flipped half of them and basically repeated the same bit 8 times on this pillar;
Ive just spent around 2 hrs searching the net for info on this topic adn the best ive found is a few people illuding to the idea that Flipped UV's in UDK are a no no and perhapse i need a programmer to write me a script to re flip the normals as they are being exported from max.
04-20-2010, 05:53 AM
i'm not positive, but i hear that unreal only like uvs mirored if the seam is verticle. not horizontal lik eyou have.
04-20-2010, 06:43 AM
Nice well ill give that a try right now
04-20-2010, 07:03 AM
Unfortunately no good,,, I changed the UVW's so the seam was virticle,,, here is hte result with a completely flat normal map applied.
I may not have mentioned earlier, i have triple checked that the seams are welded, i even welded the seam in the UVW map for good measure with no effect also.
04-20-2010, 07:48 AM
Like Rhinokey (http://boards.polycount.net/member.php?u=15212) says mirrored UVs aren't a problem as long as your normal map UV seam is vertical, and you have a proper light map UV set applied, and the static mesh has it's lighting baked.
Sometimes it also helps to merge the mirrored UVs in the light map UV set so they form a continuous shell and sometimes you need to keep them separated.
Here's a post (http://boards.polycount.net/showpost.php?p=1098043&postcount=635) with some links to a few light map UV tutorials in case you need it.
Just read the part about welding the UV mirror seam, I really should read threads thoroughly before replying :poly136:. Perhaps that's the cause of the problem, I have a habit of moving my mirrored UVs over at least 1 unit in U or V for baking purposes and just leave them like that.
One more thing, sometimes it's baking the lights with Lightmass that causes the seams. If that's the case change the Indirect Normal Influence Boost under World Properties -> Lightmass -> Lightmass Settings from default of 0.3 to 0 and rebuild the lighting.
04-20-2010, 08:23 AM
I did not know you could merge UV's into light map Uv's ill look into that however i would have thought that UDK just used the ones that came in with the Mesh : /
Unfortunately the problem was there before i welded the UVW seems together as well so im quite sure thats not the problem however moving them a touch out of line with eachother may help. I saw something about that in the UDK documentation, sounded pretty screwy to me but i guess its worth a try
04-20-2010, 08:41 AM
You normally would want to create two sets of UVs for a static mesh, one optimized (mirrored, stacked, etc...) for your diffuse/normal/specular maps and another with all unique UVs for light map baking.
UDK can create light map UV sets for you, however the results won't be as good as making them yourself in your 3D app of choice.
05-27-2010, 08:13 PM
change your normal map compression to tc-normaluncompressed in UDK. That should fix it:)
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