Retaining 2nd UV Channel Info

Psy-UK

So I unwrap my model in the 2nd channel so it can be all nice and prepared for lightmapping and collapse the unwrap modifier down. Now, a while later I add some more stuff to the model and need to edit the 2nd UV channel in order to make sure all the changes are corrected but all the unwrapping I did before has disappeared.

How do I retain that 2nd channel UV info?

Mark Dygert

You need to click "Reset UVW's" when you switch UV channels. It's a crazy feature but UV1 always carries over to UV2 unless you reset, then it magically appears.

This will reset the UV's in that channel to whatever the last "baked layout was" it bakes the UV's into the mesh when you collapse so before switching channels its a good idea to collapse the stack so the UV's are baked. If you don't and you hit reset, it will revert to whatever the layout was previously.

So... Collapse, change UV2, reset, open editor.

Psy-UK

Well that makes a whole lot of sense. :P Thanks for the quick reply.

Mark Dygert

Yea... wee-todd-ed! Welcome to max... In the max2012 UVeditor update they reworded the message but it still functions the same way... so its just as jacked up. HOO-RAY for changes!

percydaman

god i hate how max implements multiple uv sets. I always save my uv channels just as a back up. On more then one occasion Ive somehow jiggered them up and lost one or the other and had to redo them.

cman2k

I made a little script to do the whole 2nd-uv-reset thing. This way when I need to unwrap the 2nd UV channel, I just hit my special script button and it makes sure I never screw it up.

cman2k

for future-searcher's reference

almighty_gir

this should be wiki'd, the image i mean.

leechdemon

almighty_gir wrote: »

this should be wiki'd, the image i mean.

Agreed. It's a very small thing, but it's super important when dealing with multiple channels.

A fun tidbit on this though, is that you can very easily use this feature to your advantage when trying to atlas things together. If all your UV's are on channel 1, you can grab a set of meshes, apply a new UVW Unwrap to them all, then set it to UV2 and choose NOT to reset. Now all of your originally unwrapped UV's are all on the same channel, on top of eachother, but in the same modifier as other meshes and on another channel. Simply repack, and then bake to UV2 and boom, you've got an atlas. There's probably easier ways to do this (if so, I'm all ears!), but I like this over auto-unwrapping since it preserves all the work you've already done to unwrap the meshes in the first place.

Mark Dygert

almighty_gir wrote: »

this should be wiki'd, the image i mean.

Every time I see this pop up... I think people fail to understand the wiki and partially fail to understand polycount in general.

Polycount is a community, you are part of that community, you are polycount. It is only as great and as strong as you make it. We're all volunteers, and our time is very limited, we really can't spend that time looking for "this should be in the wiki" comments.

If you feel like something should be added, grab your shovel and pitch in, it starts at the contact us link at the top of the page.

At the very least use the contact us button to let someone know you found a nugget of joy that needs to be shared.

leechdemon

Mark Dygert wrote: »

If you feel like something should be added, grab your shovel and pitch in, it starts at the contact us link at the top of the page.

Contacted.

Not to thread-jack, but for future reference, is that the correct place to send suggestions to? I don't know much about editing Wiki's, or if normal forum members have access or whatnot, but I'd be happy to send things along as I find them. Is that the correct place?

Eric Chadwick

OK, added here.
http://wiki.polycount.com/TextureCoordinates

The contact form works ok, as Adam forwarded the email to me, to do your bidding. :smokin:

But yeah, anyone here can edit the wiki if they like. Just sign up.
http://wiki.polycount.com/HowToContribute