On Tuesday 15 Dec 2009, Curtis Olson wrote: > Hi Ron, > > Can I send you a copy of the model? I'd really like to make some > good forward progress this week, but it's not a drop everything > and get it done today sort of thing. Hey, I really owe you a > flightgear t-shirt or mug and if you help out on this, then > doubly so ... > > I did make an attempt to extract the coordinate of the center of > rotation using ac3d (I have a licensed copy here, not that I can > do much with it) but what I read out of ac3d was clearly wrong > when I tried to do an actual animation. > > Curt.
Probably the most common use of hierarchical FG animations are in retractable landing gear, so looking at some of these might help. The coordinates you get from AC3D should be correct too, but as already mentioned, (and iirc) the Z and Y axis are swapped (and possibly the +/- signs too). A few things though: If the 'natural' orientation of the 3D model is towards you i.e. facing you, rotate it through 90 degrees so that it's sideways and its forwards/backwards orientation matches the normal FG font/back X-axis. The symmetry for the left/right limbs will then be the same as for FG aircraft and handled by +/- ve Y-axis values. While you're working on getting the animations right, temporarily bind your animation axis to your joystick axis instead of the real animation properties so that you can test the animation axis and rotations just by using your joystick e.g. for checking the arms, you could bind the upper arm to the pitch axis, the lower arm to the roll axis and the wrist to the rudder axis. As with the Visual Reference Point (VRP), it doesn't really matter where the origin actually is as long as everything matches up. However, as you're trying to animate a human body, I'd recommend setting the origin at the hips. If the model is 'standing' upon a ground plane centered at 0,0,0, move the entire 3D model down so that its hips are centered at 0,0,0 and then use 0,0,0 as your origin. This way you'll be able to rotate (bend) the upper body over without having to worry about counter rotating it's legs, or bring the legs up without worrying about the body moving. As long as you get the animation ordering correct, the arms will follow the shoulders when you bend the body over. Having shifted the entire body down to center the hips at 0,0,0, you'll then need a translation animation to move the entire model back up again afterwards, so that its standing on the ground once the individual parts of the model are animated correctly, of course. Actually, I used to find that getting the animation hierarchies correct wasn't always quite as intuitive as I would have expected, so if the hierarchies don't seem to be working correctly try re-ordering them in the animation file (you may even need to apply what you would expect to be a single 'top-level' animation, which you would expect to be able to apply just once to an entire 'group' of sub-objects, to every individual sub-object for it to work properly e.g. to shift the entire model up so that it stands back on the ground again instead of being embedded up to its hips, you may need to apply the vertical translation animation to each individual sub-object. However, I think that the 'group' animation type might help here - I think this may have come in after I did any animations, so I haven't ever used it, but do I recall seeing go by on the cvs update logs and remember thinking that it would help a lot - some of the current modellers should be able confirm this). Sadly, I'm afraid that I don't currently have a working FG or AC3D here atm, otherwise I'd have a go at it for you, but I'm sure someone else will be able to sort it out. LeeE ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
