Source engine - MDL - UV channel 2

This is just an inquiry I have.

How many UV channels can be stored in an .MDL in Source engine?

Regardless of that answer, how do I use 2 UV channels in Source?

Is it automatic based on my settings in Max when I export?

Do I have to specify anything in the QC file when compiling SMD?

Do I have to specify anything in the VMT file for the VTF textures? (Thinking this most likely is where I would have to do anything)

In case you're wondering why. I'm using lighting from 3D Studio Max mental ray, to generate light-maps for the MDLs in my scene.

This creates both high quality direct shading, as well as G.I.; indirect shading, and color bleeding.

For shading of dynamic MDLs (NPCs, vehicles, players) that may interact with any of the lightmapped MDLs... I will be relying on Env_projectedtexture.

Unfortunately, the UVs made for the lightmaps, will not work well with surfaces where it is ideal to tile instead of have a packed texture map for.

Some surfaces can reuse the same UV coordinates for both lightmap and diffuse detail, but others it is more ideal for tiling to be used with the diffuse detail.

The tiling can not be done in VMT, because the UVs for the lightmap are minor-stretched, rotated, flipped, and separated to get the most out of the resolution.

I need to have 2 UV channels thus for this to work out with the best quality.

Thankfully that is this coming April, but I have to hope that it doesn't require Portal 2 to get the update.

Quote from Minotauro

One thing you could try (if this is a small scene) is to use the coordinates in UV Channel 02, bake diffuse map/spec/normal maps, combine that with the vray solution in a single texture and move the UV coordinates in Channel 02 to 01. Perhpas that could work but it would be one hell of a bad workflow if you are working on a larger map.

That is what I do so far, and for a surface where a diffuse detail would normally tile, now yields blurry low res results.

Quote from cman2k

Sorry to burst your bubble, but Portal 2 being released in April does not automatically imply that we will get an SDK update in April.This is a pretty neat idea. Despite the obvious heavy workload overhead, it could lead to really great results if it worked. That being said, I don't think that the MDL format supports a 2nd UV channel at all. I'd imagine that kind of feature is not possible to add without Valve's help, as it would involve changing the model compiler itself.

Well what about me using just 1 UV, and getting this to work?

"UnLitGeneric"


{


	"$baseTexture"			"models/NYC/WTC_Column_Lightmap"


	"$detail" "models/NYC/WTC_Column_Diffuse"


	"$detailscale" 1


	"$model" 1


}

in CSS, I use that, and only the "baseTexture" displays. I can't see "detail". But it is supposed to work. It worked in a map called dod_kolsch for Day of Defeat.