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2 UV channel problem (possible corrupt UVs :( )

I've been trying to figure out how this works, but im a bit worried my UV's might have gotten corrupted somehow and im just going round in circles, either that or im just not getting the whole workflow for multiple UV maps and have made a complete mess of things.

Basically I want to have a diffuse map on UV1, and an ambient occlusion map on UV2, but I cant figure out the whole switching between UV's thing, it just doesn't seem to work properly.

Also, when i open them with the Unwrap UVW modifier, the editor shows a front projection of the uvwmap that doesn't correspond to the actual UVs you see in the 3d viewport (as shown in the first pic below), but when i open the UV's with renderhjs's TexTools, it opens them fine, pretty weird.

Standard Unwrap modifier:
diffuseuvs.th.jpg


TexTools Unwrap modifier
diffuseuvstextools.th.jpg


AO lightmap UV's
aouvs.th.jpg

I'd really appreciate anyone having a look at it, you can download a sample here:
http://www.esnips.com/doc/e8bdd353-2bd6-43f8-9296-366017d882af/UV_Sample

I've tried copying the uv's from one mesh to another while changing the UV channel to 2 aswell but they just dont seem to work right, please try this if you have a look at the sample and see if it works for you.

thanks in advance,

mike

Replies

  • Reverenddevil
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    Reverenddevil polycounter lvl 9
    1. Are you using a multi sub material in Max?
    2. Are you assigning Material IDS?
    If no to eother one of those it will not work and you need to make sure if youre using to 2 uv channels say for UE3 then you need to make sure you have 2 unwraps on your object and you change the UV channels.
  • Ghostscape
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    Ghostscape polycounter lvl 13
    The two different "diffuse" UVs issue you have is because your bad UVs are on channel 2, and your good ones (the ones that show in the Max Viewport) are on channel 1. Max will only show cahnnel 1 in the viewport by default.

    It looks like your AO UVs are also on channel 1...are these on a different model? If so, save out the UVs and then load them into channel 2 of your first model. In general, though, you shouldn't transfer UVs from one mesh to the other because sometimes you can add an extra vert or otherwise fuck up the vert order and it will not save/load the UVs nicely.
  • Mark Dygert
    Yep like ghostscape pointed out max defaults to channel 1.

    You're material is set to use UV channel 1, change your material to 2 (or whatever channel your good UVs are on) and it should display correctly.
    GradientSample02.jpg
  • mikebart
    thanks for the help guys, I think i've got my head around it now, I got the light map directx shader working and it all appears fine in viewport, seems like this function could be made a lot less confusing if there was just a simple tab or something in the UV editor to select UVs, e.g; UV1, UV2, etc...

    cheers!
  • Mark Dygert
    GradientSample01.jpg
    To switch between UV channels you toggle that channel setting. Sometimes UV1 shows up when you switch to UV2 just hit reset UV's and it will bring up the correct lay out.
  • mikebart
    thanks vig, yeah that makes sense
  • Dreamexpress
    Do anybody know of any tutorials on how to bake a AO map on stacked uvs?

    Is this what you are trying to do here? Did you manage to do it?
  • glib
    mikebart wrote: »
    I've been trying to figure out how this works, but im a bit worried my UV's might have gotten corrupted somehow and im just going round in circles, either that or im just not getting the whole workflow for multiple UV maps and have made a complete mess of things.

    Basically I want to have a diffuse map on UV1, and an ambient occlusion map on UV2, but I cant figure out the whole switching between UV's thing, it just doesn't seem to work properly.

    Also, when i open them with the Unwrap UVW modifier, the editor shows a front projection of the uvwmap that doesn't correspond to the actual UVs you see in the 3d viewport (as shown in the first pic below), but when i open the UV's with renderhjs's TexTools, it opens them fine, pretty weird.

    This looks like a case of 'max is stupid'. It took me a while to figure this out too after coming from the world of maya where uvs are handled so much better.

    After changing to channel 2 in the edit uvw panel, you need to hit the 'reset uvw' button before clickign the edit uvs button to open the editor. It will throw a warning about destroying something, ignore it because it's meaningless. Renderhjs' textools do this for you automatically, thats why that warning comes up when you click open uv editor and have something other than uv channel 1 selected.
  • renderhjs
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    renderhjs sublime tool
    glib wrote: »
    ... Renderhjs' textools do this for you automatically, thats why that warning comes up when you click open uv editor and have something other than uv channel 1 selected.
    I added that in TexTools because the workflow in Max did confused me the hell. I wish I could suppress the warning message via scripting but thats how max works at the moment.
  • mikebart
    Do anybody know of any tutorials on how to bake a AO map on stacked uvs?

    Is this what you are trying to do here? Did you manage to do it?

    yeah i managed to do it, basically i've got 2 different UV channels on one mesh, UV channel 1 has the stacked UV's with the diffuse, normal and specular etc... and UV channel 2 has totally unique UVs, which is where im baking the AO onto, you just need to select UV channel 2 in the render to texture dialogue, its almost, pretty much the same process as baking a light map.

    keep in mind that having a second UV channel doubles or sometimes even triples your vert count, or so i've been told.

    @glib; yeah i've been using max for almost 10 years now, i usually find enough info online to solve a problem im having, but this had me completely stumped, lol.

    @renderhjs; thanks for making UV unrapping less of a shitty job :), its a great tool, ill never unwrap without it now
  • Mark Dygert
    Yep that warning message is so annoying...
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