The "stepping problem" I referred to has to do with the number of possible colors and the time it takes to load them.
If colors had only a red component, suppose, there would be 256 shades of red. Because this is the case with grey heightmaps (only 256 shades of grey), there can only be 256 heights encoded. The obvious solution is to use all four values of color to encode more data, but this is computationally unfeasible. If you have a heightmap made with the two colors (0,0,0) and (1,1,1), there would be a jump between height levels wherever black meets grey. That is a problem, because it jagged-izes the smooth terrain into stairs where different values of grey met. Ian
