material IDs and UVW Unwrap help

[Anonymous]

I have created a single mesh character and assigned 3 sets of material IDs;

1 = all clothes items

2= all skin and mouth

3= hair and eye lashes

I applied an UnwrapUVW modifier and unwrapped each material ID at a time

*This is where I may have misunderstood and gone wrong*

I filled the texture space with each material ID one at a time, so at the end when I view all material IDs they are all sat on top of each other. As far as I could tell this would be fine as each material ID would ultimately have a different texture applied to it through a multi/sub object material.

However, when I try to bake normal maps for the model through the render to texture dialogue I end up with all 3 material IDs laying over each other on the bake.

Hopefully someone can steer me in the right direction as to what I have done wrong!

[Anonymous · Accepted solution]

1. You can work in a copy, split the model by IDs and do each UV as a separated render to texture.
2. As alternative you could select each ID before do the render and move the UVs of the unselected ID faces outside of the main UV space. This can be useful when you don't want to detach the geometry as it can break smoothing groups in some cases.
3. Another alternative is to work with a copy and assign different UV channel to each ID. Then when doing the render to texture assign the correspondent UV channel for each render