UV Errors on UDK Import

Sean VanGorder

Wasn't sure if I should post this in the UDK thread, because I'm not sure which program is actually causing the problem.

Recently I have been having problems while trying to import meshes into UDK. A message will come up saying that I have UV layout problems, even though I unwrapped them correctly in 3ds Max. I have solved the problem before by merging the object into a new scene and exporting it again, but it doesn't seem to be working this time. I have been using Textools to unwrap my objects lately, and I THINK that may have something to do with it, but I'm not sure if that is even possible.

Here is what my UVs look like when I import into UDK. When exported from 3ds Max I have them layed out correctly. Any idea what's causing this?

Progg

Pardon me for being a Max noob but is it possible to collapse history ... similar to Maya deleting object history. It may be one option to try if you haven't.

Seems like it is storing something from the Unwrap program. I've seen something similar in Maya when using Roadkill to unwrap. Did you try exporting the model out as an obj and reimporting it back in.

Not gonna lie, that image scares me.

Sean VanGorder

Ha, yeah, I was terrified the first time I saw those UVs. I've collapsed the stack multiple times in Max, doesn't seem to help.

I was going to edit my original post with this, but since someone already replied..

I got the UVs to import correctly by applying a default material to my mesh before exporting it. When I had exported it the first time, it still had the checkered test map from RenderHJS's Textools applied. Not sure if that was what was causing the problem, or if it was just a strange coincidence.

EDIT: Yup, just tested it. I reapplied the test map from Textools and exported, and my UVs were screwed up in UDK. I applied the default gray material from Max and exported and they were fine. Do you need to have a default material on your mesh for export, or is that just an issue with the Textool maps?

Progg

Damn that was going to be my next suggestion after the export obj. Glad you got it to work. Roadkill and pelt mapper do that in Maya. They apply a custom shader to the mesh that is suppose to be removed when you close the application, but sometimes I've seen them bug out and keep the material and it causes all kinds of weird problems.

I would assume that is the same problem as Textools

Xoliul

Isn't it just showing you UV1, instead of UV0? That's a strange thing about Unreal, it shows you the UV channel the lightmap is set to. In UDK that defaults to the second channel.

Sean VanGorder

Yeah, by default it shows you UV1, but it showed the same UVs for UV0 as well.

Ott

Take a screenshot of your export options box before you export it out of Max. I assume you are resetting XForm before exporting as well.

kdm3d

The error your getting sounds like it referring to your UV2 in max (uv1 in UDK). Collapsing the stack wont have anything to do with it. Max works well with modifiers (cough max fanboy cough)

Before you export, double check your uv's by adding 2 unwrap UVW mods on it. One set to 1 and the other set to 2. On your second one, make SURE you hit reset UVW's. This will make sure you are gettign the propper channels. If either of these look like the above, theres your problem.

Adding a material to it shouldn't affect it's UV's. But to get it to read materials in UDK, you need to have a standard material applied to it with SOME kind of bitmap in the diffuse slot.

As far as I know, the checkered material you are seeing when you import to UDK, is the default material in UDK, it may just look the same as the textools checker. As far as I know, you cant import materials like that directly.

*Edit
Also, if that is the model in the background of your UV's there, it looks right. Seems like its just your UV2's that are messed up.

Try adding your two UVW unwrap mods. and on your second one, just change it to channel two. but dont hit reset. If UV1 is all unique, this wil lmake it uv2 as well and should work well with UDK.

God I'm confusing myself...

Sean VanGorder

Ott - I'll try to get a screenshot for you once I get back to my home computer.

kdm3d- Ha, thanks for the suggestion. I'll try that out to see if it fixes the problem as well. Like I said, taking off the Textools checker map and exporting it again seemed to fix the problem. In the shot I posted, behind the messed up UVs, that IS my model and the texture looks right on it. But I get the UV errors on both channels. When I fix it and reimport it, the Unreal checker texture updates and scales up. That probably doesn't make any sense. Once I get home I'll try to get shots of what I'm talking about.

Thanks for the responses!

moose

try resetting xform and exporting again?

are you using ase or FBX?