Feature request: RGBA detailed composing on export

[Mikea]

Feature request: More detailed channels composing during 'Material Export (F10)' dialogue.
In current state it is already a powerful tool for creating not a single RGB but RGB with alpha, composed of 2 different channels.

The idea behind this feature request is simple - allow compose different material channels into one single RGB map:
For example: specular to R, opacity to G, Subsurface to B, Ambient to A, so it will be full RGBA map containing all important channels in one. Handy, isn't it?

[Greg Croft]

To answer your question directly, you can do this. Everything available in the combos for RGB and A are render modes, the same render modes available for display in the tree window. The shader files for these exist on disk in <app install>/render_modes. You can edit them or add your own new render modes to achieve that sort of packing. However, specular is a color, subsurface is a color and amount, etc. You would have to convert these to grayscale (which we have utility functions for) and/or pack the data in some fashion to fit everything you listed into one RGBA texture. Even then you would be losing information, but you could do it.

But export material is really meant to bring the material back into SpeedTree, and the defaults are probably the best setup to do this. Are you using SpeedTree Cinema or one of the Games products (UE4, etc)? The above would be the method you would use for Cinema. But for game exports, you have a separate system called texture packing. These files are in <app install>/texture_packing. These are specifically meant for the situation you describe, where you pack all the source textures needed for a tree into a specific texture setup for your game, where different things are stored in different channels.

Hope this helps