Using imported UV2 for baked lighting doesn't work

I'm currently using UV0 and UV1 for maps and detail maps but I want to be able to use UV2 to be used for lightmaps.

I'm exporting this as FBX from 3dsmax, which means UV0, UV1 and UV2 correspond to map channel 1, 2 and 3 respectively.

The problem is that Unity ignores UV2 and seems to be using UV1 coordinates for light baking. I don't understand why this happens since Unity has an option to generate a separate UV2 if we decide to generate lightmap UVs inside Unity.

Shouldn't it use our own UV2 if present?

Thanks!

 

I think UV2 is reserved for realtime GI. UV1 is for traditional lightmaps.
You can tell Unity to create UV1 at import or use your own and UV2 when preparing realtime GI (or use UV1 for that as well.)

See here:
http://forum.unity3d.com/threads/quick-setup-for-starting-enlighten.309609/#post-2122729

 

Thanks for your reply Findus but that's the thing, using UV2 created by Unity allows it to be used for baked lightmaps, I just wish we could use our own UV2.

 

Just to avoid any confusion: UV2 is reserved for realtime GI, not "normal" baked lightmaps. Those always use UV1 as far as I'm aware. The only thing you can do by default is tell Unity to use UV1 for realtime as well.
Sorry, don't really have a solution other than maybe creating your own material variants that e.g. take detail UVs from UV3. (Or UV2 if you can tell Unity to let that completely alone and don't need realtime GI. ) Seems easier than the other way round, at least for someone like me with no programming experience.

 

I see, thanks again. I prefer not to mess with creating new shaders, not worth the time. I'll probably bake it in the uv1 and discard what I'm using the detail maps for.