Congratulations!
I cant really put it on top of another texture and expect it to be obvious. I need to have the diffuse texture accomodate the cubemap reflection areas!
Its true. RGB add & mul color treatment needs the base texture be neither too dark nor too light so there is space for specular addition on light colors and the dark parts of the texture are light enough to become a visible gradient when multiplied by the diffuse term.
Maybe you want take a look to RGB<->HLS conversion. It is not really cheap but lets you modify the colors in a different way. While hue could remain unchanged you could use the diffuse and specular terms as lightness multipliers and the enviroment map as saturation modifier so both layers could have some presence in the final color.
I remember a forum member publishing a shader which texturized the model with a simple image as enviroment map in screen space and a very cheap manner. The enviroment map was like a projection of an sphere and the shader computed its sample coordinates in base to the view direction vector so it gived the sense of an enviroment map but always aligned to the view, if i am not wrong. Does someone remember it? I can't find it
