Animatable megatexture test

Test of heightfield raytracer generating megatexture tiles on demand, causing additional detail to appear as camera moves closer to the ground. The principle is similar to Google Earth except the tiles include procedural bump shader data, specular, etc. In all, over 320 tiles were generated taking over 1.3 GB. Once the tiles are made, the flyover can be re-rendered much faster. No antialiasing was used, so temporal noise may be evident in distant areas.