Topic: [UDK] Blender UV problems

[ward]

Any automated ways to fix the darker parts? Sometimes it seems fixed by rotating the corresponding UV island as far as i can remember. I kindof gave up on UDK because of this and the removal of foliage since last year. I hope someone here knows what the exact problem is and how to fix it, this was exported as FBX.

[kat]

There are a couple of 'darker' areas on the mesh that look like they're cause by 'bad' mesh smoothing (either the exporter isn't keeping them, corrupting them or the mesh doesn't have any). So, check the FBX exporter is properly exporting smoothgroups and/or you applied any modifiers before exporting (depending on Blender version). Try that and see if it fixes it.. if not post (or send) the *.blend if you can.

PS: you should be able to use the [ img ]image url[/ img ] tag on imageshack files (remove spaces).

[ward]

Thanks for the fast reply, the FBX exporter from blender 2.49b does not export smoothgroups, I used the edgesplit modifier to get sharp edges. Blender 2.5x produces FBX files that crash UDK, and with ASE I keep having trouble.

Btw thanks for including the image, I figured it was too wide for that so I linked it. (and in forums they freak out about that lol)

[kat]

Hmm.. What sort of trouble are you having with 2.49 exported ASEs? The script should be saving those in a way that UDK understands.. mind you, that assumes Epic haven't changed something in UDK since the last time I used it. I'll have to update and test to make sure.

No probs re. the image, the forum should auto-resize but sometimes it breaks depending on the source.

[ward]

You mean this script right? http://www.katsbits.com/files/ase/goofosASE-2.44v0.6.10b_UT.zip

I'll just try it again and post my results. So if I just apply an edgesplit modifier first, it will automatically create proper smoothgroups for me? (Like this article: http://www.katsbits.com/tutorials/unreal/setting-up-smooth-groups-correctly-in-blender.php)

[kat]

Yes that's the one, works with 2.49b despite the filename. And yes, make sure you 'apply' the modifier before export otherwise it'll be ignored (iirc). Do a test export first and assign the modifier just to make sure it's working, if it imports properly (you should see the facets associated with the smooth groups) go back and set the smoothing up as per what you want (using 'sharp' edge marking) on the mesh if it the mesh.

[ward]

I tried that script, and from what I see in UDK with UV overlay it seesms to have screwed up one of my 2 UV layers, in UDK it's layer 1 (0 and 1 being used). However, the layer order seems to be inverted relative to the layer order in blender (or it scaled down my UV map for my materials, which of course is out of bounds, since i use tiling materials).

[kat]

OK, remove UV2 and re-export, you need to make sure that smoothing is being exported prooperly first... if that works then you know for definate there's an issue using a second UV layer. If that's the case then it means trying to figure out a way around that issue; doesn't UDK have the ability to generate a lgithmap UV layer on models? If it does it might be worth ditching UV2 in Blender and using UDK for that.

Just thinking about it actually, it may be because you're mixing UV map types so trying to use both on the same mesh may cause a problem regardless as to what you do to the mesh UV to fix it, it's probably always going to automatically re-map UV1 to match UV2 (within bounds that is).

[ward]

UDK can repack UV's into a channel of your choice, maybe that's good enough to create a lightmap from the material UV's, i'll try that (after exporting with just one UV layer containing my material UV's) and post my results, thanks again.

[ward]

I just tried and the problem remains the same, UDK seems to rescale my UV map. Also there are no material slots exported with the script, everything is one single material.

[kat]

Can you send me the *.blend (include the ASE file as well)?

[ward]

Yep:

http://www.filefactory.com/file/cb38d04/n/TestCase.blend
http://www.filefactory.com/file/cb38d05/n/TestCase.ase

[kat]

Stick um in a zip and email them, that site gives me problems when trying to download files from there - info@katsbits.com.

[ward]

Done, not as zip though sorry, nothing available to make zips atm.

[kat]

No probs, files received... OK there are a couple of things you need to look at;

1) remove all *dead* material references from your models, especially so if you're exporting *sections* of a larger mesh broken down into smaller more manageable model units - this tends to leave unwanted assignments on the smaller sections that cause trouble.

2) you ideally need to have an actual bitmap image associated with both the individual materials and the the UVW map applied to the mesh, if there isn't one there the exporter simply assumes a 'blank' mesh (so to speak) and appropriately formats the resulting text file - physical texture assets are actually needed because that's what game engines latch onto for shader/material path information; when you look at the asset browser/editor, the 'path' info you see comes from the presence of the texture when the mesh was exported.