--- Andy Ross <[EMAIL PROTECTED]> wrote: > Tony Peden wrote: > > BTW, you will rarely see the c.g. used as a reference point for > > dimensions on aircraft. First of all, it moves in flight. Second > of > > all, it's very difficult to actually point to its location. > > That's my intuition too. David is correct, though, that most > lightplane POH's use a nominal center of gravity as the origin for > their weight & balance tables. The front seat is N meters in front, > the fuel tank is M meters behind, etc...
Hmm, I thought he said just the opposite. At any rate, Cessna does not use a nominal CG for weight and balance in the POH. They use the lower forward face of the firewall. > > But still, the goal here is to make communication between 3D artists > and aero modellers easy, not necessarily to adhere to pre-existing > conventions. An artist using Blender is much more likely to be > working from a 3-view or a photograph; the c.g. isn't marked on > these. > > Picking an easily recognized spot on the airframe seems like the best > convention. Whether that be the nose or not, I don't much care. > Other good choices would be the nose gear base, wing root, tail, top > of the vertical stabilizer, etc... The nose seemed straightforward > to > me. > > In this case, the simplest solution is to bring up the 747 model in a > (registered) copy of AC3D, drag it around so the nose tip lies > exactly > on the origin, and save it. I can do all but the last step. :) But all the FDM's (AFAIK) are still pumping out position info for the CG, so if the model uses this point to rotate about, then the model won't look right (without doing some additional math). > > 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 > > __________________________________________________ Do you Yahoo!? HotJobs - Search new jobs daily now http://hotjobs.yahoo.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
