David Megginson wrote: > 1. Put the X axis origin at the published weight-and-balance reference > datum. > 2. Put the Y axis origin at the centreline of the plane. > 3. Put the Z axis origin [where? the ground?].
I'll just state my opinion again, and then keep my head down until someone tells me where to move the origin. :) Whatever convention we pick should be an easily explainable and identifiable from the *shape* of the airframe only. Not everyone has a POH handy, very few people have W&B or C.G. numbers, and even things like the centerline are subject to argument on some aircraft. Referencing the ground plane is especially bad, since the gear are going to compress differently depending on load. Remember that many/most 3D model authors aren't particularly interested in aerodynamics, and may very well be working from photographs and 3-views only. Forcing these people to look up a reference datum from an unfamiliar source is only going to discourage them. I continue to like "the origin is at the tip of the nose". You'd have to look really, really hard to find an aircraft without an identifiable nose. And finding an aircraft author who doesn't understand the concept is literally impossible. And, quite honestly, what's the actual advantage to using a reference datum anyway? No one does weight and balance calculations in Blender. :) 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