If you have photoshop CS6 extended, there's a fine 3d engine in it now. It's not as powerful as most of the real 3d software (like blender or 3dsmax), definitly not map-orented and not that easy to use at first, but i think you can already make some fine 3d work just with that. I'm currently in process of learning how to use it well, and the results i got are satisfying for now, the "convert layer to 3d form" is actually pretty handy to shape planets and simple editable forms. It all depend on what you wish to achieve in the end.
Sorry, I haven't been back to this site in a year or more. For that map I drew the grayscale image in Photoshop, but you could use gimp or anything, I like to use google maps then select broad regions and fill them with colors to recreate the terrain in a 3d editor.
Originally Posted by whtemple1959
So that particular map was done in a game engine called Unity 3d. It has a whole set of brushes/etc so you can deform terrain and texture it by just drawing with the brush. You simply import a heightmap for the base terrain with a couple clicks, then smooth it out with one of the brushes and you can draw trees/plants/textures with the brush. Extremely intuitive. Then you can throw buildings out and move/rotate them with the mouse.
But now I've switched to doing heightmaps in Blender because I need low poly terrains to run on mobiles and Unity's terrain gives you less control over polygon count.
In Blender I take a heightmap from photoshop and displace a plane to recreate the hills/valleys/etc. Then in Photoshop I select different shaded areas of gray and replace with my textures, then apply it to the mesh in blender, then import it into Unity to use in games.
I'll try to make a tutorial today if I have time, I just bit the bullet and learned the "blender" way yesterday and once I figured out how to do it, it's awesome.
The game engine Unity 3d has a really awesome set of terrain tools. You can paint on textures with a brush, manipulate the height/shape of terrain or generate it from heightmaps.
Now I've moved to Blender because the meshes are a lot more efficient for games, but it's more difficult to texture, it is really awesome..
I didn't see any mention of SketchUp in there, so I thought I should throw that one in. It's not so good with terrain, in my experience, but it's terrific for buildings. And it's relatively easy to export the geometry to other programs with better rendering capabilities.
Also, Google maintains a warehouse of free 3d models for SketchUp for use with Google Earth, so if there's a major building you're interested in, chances are good that you can find a reasonably accurate model of its exterior ready-made. I have in the past used a workflow that involved importing a building from the warehouse into SketchUp, then sending it to Blender for clean-up and conversion, and then to Maya (which is definitely not free) for texturing and animation. The texturing and animation could just as well be done in Blender, though.