Today's challenge has been in remapping the height ranges on the heightmap so that both the lava and the land go from 0-1 while maintaining their relative heights. Or to put it another way, making sure the upper boundary of the lava colour gradient matches the lower boundary of the landmass colour gradient. I'm still not completely happy with it yet, but we're just about there.
Here's an example of a lava world with a tenuous atmosphere and sulfuric clouds:
The landscape shader takes the relative height of the lava into account when defining its regions, and I'll be driving that value using the planet's kelvin temperature on the procedural generation. Here's what it looks like when you turn up the temperature on the same planet :)
I'm going to add a bit of heat haze to the lava next, and then I'm onto the final polish for all the various flavours of exoplanet generation. Oh, and I've also had a good idea for how we can create a single circular sea of lava for tidally locked worlds, so I'll take a quick look at that too :)