zaai999, I actually didn't want to show too much of the lava... I originally wanted to only have some red glow coming from the depth of the canyon, but when the plane having red luminosity turned out to have a nice appearance I decided to show it at least to some extent. How do you suggest I improve the surfacing of the walls (there are quite a number of shaders at work already)?
As for the glow, it is in part the luminosity of the plane (at least I assume so), but largely an additional red light source. The walls are actually black. There is a third light source illuminating the clouds on the left from below.
