One of the last extension libraries I wrote in OpenScad had to do with height maps.

This thing implements height maps in Banate CAD.

You can read the blog entry here: http://williamaadams.wordpress.com/2011/11/25/and-height-maps-for-all/

It's fairly straight forward in Banate CAD to do a height map from any image. It's actually the ImageSampler object that has the capability. You can then add this to this other object called a RubberSheet, and away you go!

You can also specify a thickness, so it's not just a surface, it's actually a solid.

The image with the purplish background is the generated mesh loaded into MeshLab. MeshLab was kind enough to remove the duplicate vertices for me. I'll have to do that within Banate CAD itself some day.

1) Download image
2) Print
3) Rejoice!

For the adventurous, go download Banate CAD, and get the .fab file, and start playing around with things. The blog entry might give you some hints and ideas.