At the moment i use for environmental mapping GL_ADD_SIGNED, which yields to pretty good results.
However i was wondering if there is a possibility to control how much the environment gets reflected. For example an iron object reflects the surrounding quite perfect, but sheet metal (if that´s the word), like a dirty car reflects the surrounding not that good. So from the car you would see mainly its texture and the environment gets only lightly reflected.
Is there a way to do this? Maybe using the primary/secondary color to influence the reflection?
But i have to admit, that i don´t know much about extensions like texture_env_combine. If someone knows of a good tutorial about this extension i would be happy already.
Thanks.
Jan.