Multiple UV Channels in Max 2008...
polycounter lvl 10
Hey guys.. So I'm trying to apply a 2nd and 3rd uv channel to an object in Max. I do a UV Map modifier, select channel 2, and apply it. I go into the Unwrap, and it's using the same UVs as channel 1... I've tried applying it in different ways, and nothing works. One thing I have noticed is that in the past when I've used the UV Unwrap modifier, it gives me a little warning every time I switch between channels. That warning isn't there anymore... Any ideas?
Replies
Try doing something like adding a UVW Map modifier (plane/box/whatever) and make sure it's set to channel 2, then add an Unwrap UVW and see if that makes any difference in channel 2.
2nd If you're switching back and forth between 1 and 2 it sounds like its resetting to default which is the last "baked" layout. So either be prepared to do a lot of loading/saving each time you switch (by changing the channel) or instead use two UVW unwrap modifiers. One set to channel 1 and the other set to channel 2. Toggle on and off the visibility of the upper most (click the light bulb in the history stack) normally 2, when you need to work on the bottom.
You can edit channel info (delete any unnecessary channels) by going to Edit > Channel Info. Know that every object has a few channels to start with so not everything is useless. Extra UV map channels will show up as #:map. The following are normal and shouldn't be removed: mesh, vsel, -2:Alpha, -1:Illum, 0:vc.
Note: Make sure you collapse your stack first or add another edit poly and unwrap before doing this. Otherwise you will overwrite your UVs.
I have to do this for light maps for ue3 so I will do all my unwrapping on channel 1 for my diffuse, spec, normal, etc and then once done collapse.
I get my textures fully painted and complete and before exporting I will work on my second uv set for the light map and once that is complete I will collapse the stack and then save and export.
http://area.autodesk.com/index.php/forums/viewthread/1110
Not sure if that's exactly related to the above issue, but it's beyond frustrating.
What's burning me now, is that I cannot farkin SEE my UV channel 3 edits in the viewport. How the hell am I supposed to know the texel density if I can't see my damn texture! GRRRrr
What's burning me now, is that I cannot farkin SEE my UV channel 3 edits in the viewport. How the hell am I supposed to know the texel density if I can't see my damn texture! GRRRrr
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Thats because your diffuse map material is set to use channel 1.
You could copy your material to a new slot, and change the Map Channel to 3, then just assign that material when you want to view Channel 3. It wouldn't be too hard to write a script that does that for you, then you can bind that to a key stroke or a button.
Damn, I could have sworn I saw them work in the viewport (on a single material) in the past.
That's what I get for being out of art for 2 years.
Thx Vig, Ruz
So if you go to map chan3, it will auto-copy the chan1 UV's into it. You can then hit 'reset' if you want it to default to a generic planar map. From there you just map as you normally would. Once you collapse the stack, you can still access everything just fine. If you apply a UVW UNwrap and channel 1 is selected, if you hit channel 3 it will re-copy channel 1 UV's again. But then you hit "reset uvws" and it will bring back the UV's you made earlier. So while it temporarily erases the UV's, they're not really gone.
Though if a person didn't know about the issue (as most of us do not) it would seem like a HUGE bug.
Or go to Edit > Edit Channel Info find the channel and "clear it" which does the same thing. To me it makes sense to have that in the modifiers GUI and not handle it with another modifier but, meh, semantics...