http://en.wikipedia.org/wiki/Myth_%28computer_game%29 On the Myth series of games, by Bungie, explosions, blood and just about everything else can permanently scar the landscape. This is done in a way that doesn't seem to occur any texture memory overhead. I'm assuming that the landscape is implemented as a normal OpenGL textured mesh, so how is the texture modified so efficiently in real time? Bear in mind that the first version of this game came out in 1997. As far as I can tell, the explosion scars are implemented as small decal textures and are somehow modulated with the large landscape mesh texture, but this is quite beyond me. Any ideas? code?

Judging from the screenshot (never actually seen/played that game), the landscape was using a single texture (or a set thereof). The easiest way to achieve the effect probably was to just manipulate the texture directly by painting additional onto it.
This would have been both, simple and effective.

Regards,
Pat.

Yes, the mesh texture was indeed a single texture (or set).
Creating maps for the game was really just a case of creating
an image and height map in an image editor.

I'll look into your suggestion, thanks.