ROAM newbie questions

Hi. I’m new to terrain rendering and I have a couple questions regarding the ROAM algorithm and other clod algorithms in general. What is the exact relationship between one point on the heightmap image and one patch in ROAM? What I am getting at is that I don’t quite understand how level of detail is actually achieved. How are height values between points on the actual heightmap determined? Thanks in advance.

try google. there are nice pages explaining roam out there
try other forums. it does not depend on graficsapi, so it does not on gl, and you say its a newbie question so don’t ask in the advanced boards…

oh, and in my eyes, don’t bother with roam, its too cpu intensive for most applications (except if you want to lod a whole planet or what ever…)