hah, i knew offering free screen shots would get you to read this, just give me your credit card number to confirm your age and everything is free!! erm.. heh, just kidding. anyway,
After a bit of vacation from graphics prgamming im back!
I decided to re-write my terrain engine from scratch. Im implementing a LOD (Level Of Detail) system based on Roettgers Algorithm. So far ive just finished the distance based part of it, next up is to add the interpolation error calculations (keeping a min level of detail for "rough" regions independent of distance to the viewer) and geomorphing so vertices "popping" in and out arent noticable.
Here's a wireframe screen shot of the distance based LOD in action. The view point in this scene is the corner near the bottom of the image (a little out of view). Notice how the area near the viewpoint uses the most detail (high number of tri's). As the distance to the viewer increases the detail does too! This is totaly dynamic and updates every frame as the viewpoint moves. My implementation uses triangle fans and performs T-junction elimination as well.
*Note: Frustum culling is not enabled in this screen shot (even though it kinda looks like it ) Im just viewing the mesh from the corner.