View Full Version : render to texture with face mapping?

01 January 2007, 11:54 AM
I am using 3Dsmax8

I have a question which hopefully someone out there has a solution for. I have been working on an environment and have been utilizing face mapping techniques for UV mapping the texture, meaning UV's are overlapping for different parts of the environment faces. Now the trick has come and I have been asked to apply a shadow map to the environment. Unfortunately using the "use existing map channel" in render to texture is not going to help me because UV's are overlapping and would cause artifacts. The current workaround I have found is to apply an automatic unwrap just for shadow baking purposes and then input that new map into the self illumination slot of the texture and have it use the second channel. Basically applying two textures to the same mesh using two seperate UV channels. Automatic unwrap is hideous though, completely disgusting as it breaks the entire mesh into tiny fragments, thus resulting in UV's which produce both crap shadows and at different resolutions and being basically useless, but its the only way I know of.

Apparently face mapping is the hot thing to do these days and more places are using it but I'm left scratching my head when it comes to baking shadows and using render to texture for anything using this technique. Any ideas, suggestions, shared frustrations?

01 January 2007, 01:20 PM
you can peltmap the whole mesh at channel 2 and "use existing channel" 2

01 January 2007, 06:07 PM
Why not move the mirrored parts out of the way? use the offset function in chuggnut's unwrap tools:

Also you could save your UV layout from channel 1 and apply it to channel 2 and then modify it instead of using auto unwrap.

01 January 2007, 07:53 PM
You can do offset in the standard max unwrapper. Just switch the coordinate system to relative by clicking the little icon next to the row of the coordinates at the bottom left.

01 January 2007, 09:45 PM
Hey Art,

when you auto unwrap and bake a lightmap to that new channel it comes out bad? Is it jaggie or what? The UV coords should have little to do w/ the shadow map quality, but I may be mis-reading that. We have to do something similar at work so that the Unreal Engine can bake a light pass to a second map channel. I usually do just that, a quick auto unwrap to a second map channel and it comes out fine.

Either way, looking forward to seeing a new environment from you!


01 January 2007, 05:44 AM
For Automapping AO maps just use a second UV layout. Tyler was right on the money.

If it still looks bad, mess with the settings a little more on the auto unwrap.

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01 January 2007, 05:44 AM
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