Playable Heightmap

Question

I have a game with infinity procedually generated terrain. I'm using 1/f noise for the height (I think this is perlin noise?). Anyway it looks nice, but its not very playable since it doesn't really have flat areas. Just decreasing the amplitude won't work since I still want a large variation in height. Does anyone know of a filter I can apply to the heightmap to encourage flat areas while keeping a large range of heights?

Written in C#

EDIT: I've realised that what I want is for steep gradients to become steeper, and for flat gradients to become flatter. The terrain needn't be realistic, just "fun" for an FPS.

Answer 1

I believe you need to use a smoothing function to get rid of the jaggedness of the terrain, if that seems to be your problem.

I only glanced through this page, but it may be a decent guide: http://www.float4x4.net/index.php/2010/06/generating-realistic-and-playable-terrain-height-maps/