On Hold How do I assign collision to my map?

I am making a map in sketchup, but before going too far into it, can anyone give me advice on how to get it to have collision?

I don't want to be done and have a big mistake and have to start over.

 

How come no one ever replies to my posts. So far on my 2 other posts not one person replied!

 

Hm not sure why People dont speak with you. XD
You may want to take a look at this Thread and check for the System/Structure Torque3d uses to actually create a Terrain from a imported File.
Which would be a Heightmap in Black and White, so you would have to get a Heightmap from the Map you create in Sketchup and import that, rather than the Map file in shape of a 3D Model.
I guess you could import it as static Object too and give it Clipping that way, but im not sure if that wouldn't have bad Effects on the Performance of your Map.
http://www.beamng.com/threads/2764-...depth-guide-with-pictures)?highlight=tutorial