I've tried renaming a texture that was inside a cmod sphere to use earth.png and this is what I see.selden wrote:1. RGBA textures which are applied to Celestia's internal planetary spheres have their A channels treated as specularity.
2. RGBA textures which are specified within CMOD or 3DS models as diffuse materials have their A channels used for opacity. A separate material is used for specularity.
3. RGBA textures which are applied to CMOD or 3DS Meshes using an SSC Texture statement replace the models' internal diffuse textures and have their A channels used for specularity. This is for consistency with how RGBA textures are applied to Celestia's internal planetary spheres. All other SSC texture declarations are ignored when applied to Meshes.
The alpha channel still seems to be used as opacity no matter what. In the past, I was trying to get a rgba texture to work with an empty alpha channel. So I don't know what's going on here.