CompuServe Thread

#spin independently?

5 messages in this thread
#167150From: Brent BonetApr 28, 1995 7:31 AM
I've created an animation of a camera flying around a globe. To avoid the camera flipping caused by quaternion(sp?) math in 3DS, I've linked the entire scene except for the camera and target to a dummy object. This dummy object is moved and rotated to create motion. Everything works fine but I want the globe to spin independently on one axis. I can't see to get this to happen. In fact after using link info to get what might seem correct, I seem to be getting the same flipping of the globe that occurred with the camera when I was moving it independently. Any hints? This thing is due!!! Brent Bonet – POP! Multimedia Atlanta
#167178From: Steven ElliottApr 28, 1995 11:31 AM
Brent, If I understand correctly, you are probably trying to apply too many rotations to a single object. Use the dummy object only to animate the globe with respect to the camera. Apply the spin directly to the globe or to another dummy set up exclusively for that purpose. When it comes to rotations in 3D Studio, segregation is a good thing. Steven
#167249From: Brent BonetApr 28, 1995 5:24 PM
Steve, I'm running into big probs with the quaternion stuff. The suggestions I've received haven't quite applied. Any hint on dealing with that? Brent
#167358From: BRENT W. MALNACKApr 29, 1995 4:53 PM
Brent, Our Dynamic Motion Module IPAS plug-in allows rotation to be specified in degrees per second by each individual axis. Getting the rotation conversions together for 3DS was extremely difficult. I don't know if it would compliment what you want to do or not, just thought I'd mention it. Brent
#167617From: Steven ElliottMay 1, 1995 12:01 PM
Brent, 3D Studio normalizes multiple rotations into a single rotation about a derived axis. (How's that for blowing smoke?) The simple solution is to use multiple dummy objects, one for each axis of rotation needed. This gives you very precise control without having to unduly worry about how multiple rotations are combining. Imagine a hierarchy such as the following: . dummy.roll->dummy.pitch->dummy.yaw->object You could now set-up complex rotations by applying only simple, single axis rotations to the appropriate dummies. Hope that helps, Steven