getting specularity on second life avatar

I’ve imported the Second Life wavefront meshes for male and female avatars. I’ve combined and smoothed them appropriately and set up the nodes for the top and bottom. I have 3 material nodes. There is one for the base material and has Diff (diffusion) on and Spec (specularity) and Neg (dunno :slight_smile: ) off. And there are two for specularity, both of these have Spec on, and Diff and Neg off.

I then combine the material nodes with color nodes. It looks a bit like this…

Base Material ----> Color node -----> Color node ----> Output node
| |
Specularity 1 ----+ Specularity 2 —+

I’m new to Blender but have experience with Gimp. And I noticed that these color nodes have similar possibilities of combination as Gimp’s layers. Let me use Gimp as an example of what I’d like to do.

If I have a base layer in Gimp, I can create a second layer with a pattern on it (or color or whatever) and then combine the second with the first with gimp’s layer modes: Multiply, Divide, Dodge, Burn, Overlay, etc. The second layer will be transparent in areas where the original material is not to be modified, and will have something in the areas where it is to be modified. I’d like to do something similar with blender, modifying the base material with the specularity layers.

So with all that as background - my question… (at last).

How do I make the backgrounds of the specularity layers to be transparent?

That is, I want the specularity layers to be transparent, except where they have the reflection. And, in that reflection, I would expect there to be a degree of transparency, appropriate to the reflection. For example, the leg, viewed from the back, will have an area of reflection on the calf, stronger in the middle and tapering off to the sides. In Gimp the transparancy would be minimum in the middle and increase toward the sides.

Now, in Blender, my specularity backgrounds are always be black, which leads to unwanted blacking out of the base material in the areas that have no reflections. I am new to blender, so I’m sure there’s just some button somewhere that I don’t have set correctly.

Hopefully this is clear, if not feel free to ask questions. Thanks,