Author Topic:   Placing Objects on Terrains
Bryan T
posted April 26, 2000 03:51 PM            
Topics for discussion...

How do you place objects onto terrain such that the terrain doesn't 'jut through' the bottom of the object? Does the terrain have to be flattened out at this point, or should the terrain not even be drawn over these objects?

This extends to more complex terrains: cliffhangings, rock bridges, caves/tunnels, etc. All forms of topology or construction that are not supported by a terrain engine.

Anyone have some good input on these problems?



posted April 27, 2000 08:38 AM            
I generally flatten the terrain under structures; after all, if someone was going to build a building in real life, they'd flatten the terrain first. More generally, so long as the terrain is smooth, you can calculate a normal to the terrain surface and rotate your object to be aligned with that normal -- so that you could have some structure on the side of a mountain, for example.


New Member
posted May 04, 2000 09:25 AM            
Yeah... you probably have done this already but I mark the objects area on the heightfield, and increase the variance around the edges of the area by a large amount to stop it from abstracting to a larger tri that could cut through the object. Also, I don't render any triangles in this area (although this is flagged incase there is some less-than-solid object that lets the ground show though)