For sky, the geometry doesn't matter. I use a cube map for sky, and map it on some arbitrary geometry that goes around the camera. I can then use that same cube map for reflective surfaces in the world.
Height maps are great for physical games with lots of outdoor terrain. Racing, tank battles, that kind of thing.
Mesh terrains are great for less physical games, and/or indoors games, like platformers.
Jon Watte, Direct3D MVP
Tweets, occasionallykW X-port 3ds Max .X exporter
kW Animation source code
