Jon S Berndt writes: > Found this page interesting: > > http://www.gamedev.net/reference/articles/article1817.asp > > but does this do something that FlightGear doesn't already > do?
Interesting, but this article deals with terrain heightmaps (regular grids of elevation points.) FlightGear uses an irregular triangle mesh. What we'd need to do would be (a) Jettison opengl lighting, (b) for each vertex in our TIN take a vector from there to the light source. If it intersects any other terrain, that vertex is shaded, otherwise it's not. This would be expensive to do, but we wouldn't need to do each vertex each frame ... you could maybe do a couple each frame in a round robin fashon. It's hard to say in advance if you could do this quick enough to keep the shadows tracking the sun over time ... also you'd need to consider what to do when you load a new tile ... do you prime the pump and do the calculation for all these points at load time (so it looks correct from the start) or just throw the points on the update queue and get to them when you get to them (tile will start looking wrong, but eventually the vertices will pop to the right shading.) This wouldn't address what happens if a shadow cuts across the middle of a large triangle, but it's probably beyond our means to handle shadows with that amount of fidelity. Curt. -- Curtis Olson IVLab / HumanFIRST Program FlightGear Project Twin Cities [EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
