Partial UV mapping

[bugman_2000]

Hi,

I want to UV map eyebrows onto my character. So I LSCM unwrapped a segment of the face that I want to map the eyebrows on. And I've set texture map input to UV. This works great for those faces. They eyebrows look pretty good. Unfortunately, the rest of the entire mesh, the parts that I had not done LSCM unwrapping on, is now covered with eyebrows. I know I could make a separate material for just the brow faces, which I think I will probably do if there's no other way, but it seems that there must be a way to UV map so that only the actually mapped places show the texture. Can I do this?

T

[z3r0 d]

in face select mode when you select a texture with faces selected the texture is applied to those faces

using the texface option in the material buttons [not adding any fancy textures or anything] shows those images mapped as you did in face select mode


however, if your eyebrow texture is multiple layers [say spec bump and diffuse] then you'd have to go back to the old way of using image textures mapped using uv coordinates [in the material buttons]. You can use multiple materials on the mesh to have the eyebrow material seperate from others...
http://download.blender.org/documentation/htmlI/ch10s07.html

[bugman_2000]

in face select mode when you select a texture with faces selected the texture is applied to those faces

I didn't know that, thanks. But I think I still am better off using UV mapping for this, because it gives me a little more control over the exact placement and shape of the eybrows on the mesh. At present, I have gone with using separate materials, one for the brow area and one for the rest of the face. This is fine, but it seems redundant, since aside from the eyebrows they should be the same. Like if I change the specularity on one I need to go change the specularity to match it on the other.

I'm just puzzled... if I LSCM unwrap only certain faces, then map the texture using UV, why should that texture image appear anywhere else on the mesh? Seems to me it shouldn't.

[Hazza]

The default position for an un modiified uv map has all quads pilled on top of each other and each quad uses the full size of the uv map area. This means that if you only lscm map parts of your mesh the remaining parts of the uv mapping will stay as they are so your uv image will be displayed in full on each quad of the mesh.

[z3r0 d]

you could also have all of the other faces on your mesh uv mapped to some other region of your eybrow texture which is transparent or a solid color

[unless stencils or alpha channels are involved, textures cover the entire surface the material does]

[bugman_2000]

This means that if you only lscm map parts of your mesh the remaining parts of the uv mapping will stay as they are so your uv image will be displayed in full on each quad of the mesh.

Ah, I see. That explains it.


you could also have all of the other faces on your mesh uv mapped to some other region of your eybrow texture which is transparent or a solid color

I thought of that, but didn't want to make a bunch of seams and do a bunch of complicated unwrapping just for the eyebrows. I think that the best solution for me now is the two materials.

[Modron]

one way to go about it is to select the ones you want mapped, then do a select swap, and load all those faces into the UV editor, then scale them down and put them off in a corner away from your eyebrows. then use an image with an alpha channel for the eyebrows, and make everything but the brows transparent. when you load the image in the texture buttons, click on 'use alpha'.

[bugman_2000]

Thanks for the suggest, Modron, I think this is closest to what I have in mind.