First off, Geoscape3D is a great program in my opinion that has many more options than a simple .bmp heightmap. Second off, if you want to use it with a heightmap, you can use a variety of ways to load it and place it into a matrix, but as for tecturing thats up to yuo and it will involve layering textures and shading and all kinds of crap to look like your so-called "perfect." Geoscape3D Supports exporting in .x format which works well with DarkBASIC. If you load the map as a .x object into your program:
Load Object "My_Map.x",1
It will automatically texture it if you have hte texture included in the same directory. Or you can load the texture and mesh seperately and then make the object:
Load Image "My_Texture.bmp",1
Load Mesh "My_Mesh.x",1
Make Object 1,1,1
This will make your map as an object and texture it as it looks in Geoscape3D. If you wish to do collision with an object such as this, you will need to be using the intersect command which I have not quite "mastered" yet but there are tutorials and such that cover doing this. And I believe xMik has a great program out for running collision on objects. And he has put it into easy to use functions and provided everything needed to run it in a demo and write and compile your own code. There are plenty of other ways to make maps into objects with other programs, but alot of them will require file conversion. And I wouldn't go with BSP because DBP's BSP support is messed up.
AMD Athlon 64 3200 - GeForce 6800 GT - 320GB Hard Drive
1024MB RAM