I want to animate this simple arrow object. The arrow should first spin around the pointed end, and then spin around the ring end, as shown in the picture. The object should be a single element (no multi-body), and the animation should work without cloaking. Is it possible to create this motion in Carrara? If so, how difficult is the animation setup? Thanks for your help.

It's just a matter of rotating around the hotpoint and moving the hotpoint at certain keyframes. During the first part of the rotation, the hotpoint will be at the point of the arrow. The once the rotation is complete, add a keyframe to the timeline, move the hotpoint to the other end (center of the circle) and continue the rotation.

Thanks for the information, tkane18. I thought it should work this way, but keyframing the hotpoint doesn't behave as expected. I have tried different settings (lock/unlock center & hotpoint, change tweeners, delete keyframes for some properties etc.). Not successful as yet, unfortunately. Thanks again for your support.

Hello VK, You've got some complex motions going on. Consequently, you need to have key framing that is a little more specialized. To create the motion, the object hotpoint needs to be completely at one end. After the 180 degree rotation takes place the hotpoint needs to be moved to the far end in order for the object to rotate around it.(I just manually rotated the object first one way, then the other using the shift key to constraining it to perfect rotations) The lines that you see highlighted in yellow need to have their Tweeners set to Discreet. Good Luck! Mark

You could also try another somewhat more advanced technique without having to move the hotpoint. Take the arrow and place the hotpoint at the end you want to move last. Group the arrow into a new group (yes, the only thing in the group will be the arrow). Move the hotpoint of the group to the other end of the arrow. Now, rotate the group through the first rotation. Then rotate the arrow inside the group for the second rotation. This basically allows you to have two hotpoints for the same object. Not as clean as Marks solution but this can really make a BIG difference for complex rotations in more than one plane. I've used it quite a bit in that fashion adding groups and hotpoints as needed. -Kix

-Kix

Mark, thanks for the example. Following your example, I could make it work. Now it even works with a single keyframe in the Position and Hotpoint tracks. The direction of the rotations is wrong, but this seems to be problem of the interpolation method (no quaternions), and can be fixed with a few additional keyframes. Kixum, thanks for the information. The "multi-body method" is perfect for this sort of motion. However, I want to find out, if the same motion can be created with a single object. The background story is a bit OT. I should know in the end, which animation programs have an animatable rotation-center, and how easily it can be applied. In Carrara, the Hotpoint property works very well and straightforward (if one knows how to use it, of course). I will also test C4D, EI Animator, and maybe Bryce. Poser is a little bit special, because its Centerpoint property is not animatable by default. But there's a trick to animate the rotation-center, and even use two rotation-centers at the same time in a single object (the arrow picture shows a Poser prop animated in Poser).