David Megginson <[EMAIL PROTECTED]> said: > Martin Spott wrote: > > > I can't withstand the impression that changing the _camera_ position > > didn't lead to the intended success. Take a simple stick and rotate it > > around one of its ends. For an observer the phenomenon is still the > > same even when he changes his viewpoint. > > If you want to rotate the stick around its middle you really have to > > change the centre of rotation which means, that one end of the stick > > goes up and the other end goes down. > > > > At least in the _outside_ views the PA-28 still rotates around its nose > > after the recent changes, > > That seemed funny to me as well, but when I looked from the outside view, it > did seem to pivot around the wings after the change (in fact, as I moved the > camera back and forth, so did the apparent pivot point). That was from a > side view in flight -- what did you use where you saw it moving about the nose? > > I had assumed that the property was mislabelled, and actually moved the > model original somehow. >
In the real world the eye isn't really exactly under your control. At some level either mechanically or through interpretation the brain always tries make the world look "right". With 3D that the camera does _exactly_ what you tell it to. If you tell it to point to the nose of the aircraft, it will follow it doggedly. And since the camera is always focused on the exact same spot on the aircraft, it will always appear to be stationary in the view. Same spot on your screen. Another way to look at it is this: If the aircraft pitches, the nose moves up and down. If the camera is tracking the nose, then it moves up and down as well with the nose. This creates the _illusion_ that the rest of the aircraft (and of the scene for that matter) is moving, and the nose is remaining stationary when in fact it is moving up and down. So the aircraft is always rotating around the proper location. And that's the reason for that particular property name (maybe "Camera-Target-offset-z" would be more explanatory?). Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
