I was wondering if there was anyone working on a roam terrain engine in this board.I might have a few questions I’d like to ask.

check out digital dawn, i think it is.

yep:

http://ddg.sourceforge.net/home.html

its a ROAM-based terrain source.

cheers,

John

Zen,

You can get a tutorial and article about a simplified ROAM implementation here:

http://www.gamasutra.com/features/20000403/turner_01.htm

It’s a good starting place for learning Terrain Rendering. You’re welcome to ask questions regarding this or more advanced ROAM implementations too.

–BryanNC

Getting started isn’t my problem exactly.I allready have the basic algorithm working,with both split nad merge queues but now I’m stuck with view-frustum culling.All though it’s working correct most of the time(and more than doubled the engine’s performance) I do lose a few tris now and then and I also have a few other minor bugs I was hoping I could discuss.

For bullet-proof occlusion culling:

Do it in 2d (top-down) (obviously).

You have to examine 3 cases:

- a corner of the triangle is inside the frustum. If all the corners are in then you know that the triangle is completely within the frustum (so you don’t have to test the child triangles).
- a corner of the frustum is in the triangle.
- (the case that is most commonly ignored) the edges of the triangles intersect.

Iff all these cases are untrue then the triangle is outside the frustum, otherwise it’s in or partially in.

HTH.