Michael Pujos wrote: > Yes but there are techniques to sustain high poly count, none of which > would be easy to integrate in flightgear. One great demo of high poly > count terrain rendering with LOD is the chunked LOD demo from Thatcher > Ulrich (http://sourceforge.net/projects/tu-testbed). This demo is > optimized to death for NVIDIA cards though and is well worth checking > if you have one.
Woo hoo! The LOD war is back. :) My feelings: Static geometry is good enough for almost everything these days, including flight sims. The only exception is getting the "all the way to the horizon" rendering correct for high altitudes, where visibility can be infinite and mountains 200nm away should be visible. Continuous LOD schemes are the only ones that make sense. "Chunked" LOD is optimizing the wrong thing -- Thatcher gets very high polygon throughput, which admittedly make for good flame bait. But real users can't count polygons on modern hardware, and only care that the screen looks right and the animation is smooth. For a LOD scheme the only correct metrics are (1) screen space error and (2) lack of visible "pops" or geometry discontinuities. Chunked LOD does no better than ROAM variants in error (despite using far more polygons to acheive that error), and shows significantly worse discontinuity behavior (whole chunks go in and out at once). Split-only ROAM is my choice, FWIW. You can push the per-triangle CPU overhead down to 2-300 cycles, which on modern processors is easily sufficient for tens of thousands of triangles per scenery tesselation. For real-world terrain, that's less than a pixel of screen space error. Andy -- Andrew J. Ross NextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com "Men go crazy in conflagrations. They only get better one by one." - Sting (misquoted) _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
