Jon S. Berndt wrote: > Andy Ross wrote: > > What part of "assuming a flat ground" is not getting across? :) > > I was trying to figure out where you got that 34% error from.
Sigh... grab a calculator. Type "2", then "0", then "sin". :) The answer to this question: How far from the original position is the tip of a gear strut at 20 degrees of AoA (or bank, or whatever)? ...is "34% of its length". Draw it out, if it is not clear. For small angles, that distance goes as the sine of the angle. The sine of 20 degrees is 0.34. QED. You answered that this didn't matter, since only the Z component was important. I immediately plonked you for assuming that the ground was flat (or, strictly, that the ground and aircraft's wing/body planes were parallel). The point of doing separate gear intersection testing is to get proper results when the ground is *not* flat. We *already* get proper results with flat ground. You can't fix the flat ground assumption by making the flat ground assumption. Again: if we're going to do it, we should do it right and not wrong. We already have "good enough". If we need better, we can only go to perfect. > It's been mentioned here several times in this thread already. If the > runway is not perfectly level, the aircraft will be tilted (in real > life). > > 1) If we model the gear given a per-gear elevation, we get a lot of > effects for free - including slanted runways. The 3D model with then > rest on it correctly. Ah, here's an actual feature. But the solution is wrong. If you want a tilted aircraft, then use the normal vector for the ground plane (take a look at the YASim code for this if you want). You don't need to do per-gear stuff for this. And in fact you don't want to, because of the stair-stepping effect I mentioned earlier. You can do better with a single plane. 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
