Sign in to follow this  
soconne

ridged fractal heightmap generation

Recommended Posts

Anyone know of any sites or tutorials showing how to generate ridged mountain looking terrain? I've seen terrain apps that generate this type of fractal terrain but I cannot find an explanation or source code doing it.

Share this post


Link to post
Share on other sites
There are many ways of creating such terrains, from simple to extremely complex. It all depends on what exactly you are expecting as a result, and how much control you want over the process.

For simple fractal terrain generation without much control (except a seed value), Google for "midpoint displacement" and/or "fractal Brownian motion". If you need more control over the process, then noise functions can be worth a look: Perlin noise, multi octave turbulance noise, etc.

Share this post


Link to post
Share on other sites
Actually seeing the subjectline reminds me of something I was wondering recently. In terragen, what function do they use for the "ridged perlin" method of heightmap generation?

Share this post


Link to post
Share on other sites
Probably an absolute value function on the noise. That's a common method to introduce discontinuities into the noise function. Can be used for terrains, to generate marble, wood, etc.

Share this post


Link to post
Share on other sites
One thing you want to watch out for is the 'tin-foil effect' where a randomly generated surface has roughly the same surface characteristics right-side-up as up-side-down.

That may look fine for surfaces well above the tree line, but in general most terrain is concave-down toward a gully. The absolute-value noise function is a way of avoiding the tin-foil effect, but it biases terrain upward so that if you tried to stitch together patches that were independently generated like this, there would be notable dips at the borders.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this