Are you sure you need DEMs?

You can use Fractal Terrains to render a displacement map of your terrain. It's an option under one of the toolbars, you'll have to look for it.

Once you have the displacement map you can use it to make a new terrain in Bryce. (Tell me if you would like to know how), but it may need some smoothing.

If you then want to adjust that terrain, you can export the terrain image bump map into photoshop and put in your rivers etc.

Alternatively if you have access to a 3d model package which has displacement painting, you can:

Make your terrain in the 3d package and displacement paint the mountains, hills rivers etc.

Open the model in Bryce and render it using the top camera and the distance mask. (This will give you a terrain displacement map) and make any further adjustments of that in photoshop.

I think that's what you're after (3d modelling the terrain instead of having to draw it), but if you have any questions, don't hesitate to ask.

ps. Also have a look at my 'first try at 3d maps' thread in the WIP section.

Ravs

:Edit: I find it really weird that FT can import DEM information but can't export it. I'll have to give it a try, but it won't be this week I'm afraid. Have you tried posting in the Profantasy yahoo user group? They're very knowledgable and helpful.

Ravs