Hi all

Bit of a tricky one this so bear with me :)

Imagine you have two circles, one large and one small. The smaller of the two circles is located on the circumference of the larger circle. When I rotate the larger circle I want the smaller circle to rotate with it, BUT, only at 50% (so that, effectively, the smaller circle is rotating around the same pivot as the larger circle only slower). However, I also still want to be able to animate the position and orientation of the smaller circle as I see fit whilst still being under the influence of the larger circle.
Freezing the transform of the smaller circle and then wiring the Available slot of the Position track into the Zero Pos XYZ track of the larger circle goes half way to what I’m trying to achieve. Obviously, however, when it comes to wiring the orientation constraint, the smaller circle rotates around its own central axis and not that of the larger circle. Bummer.
I’ve tried linking multiple dummy objects to create the desired falloff scenario but when it comes to wire the smaller circle to the final dummy object, all the wiring setup is ignored and nothing happens.

Any ideas?

I think you will want to look at expression controllers which are based on math.  Also, set the pivot point of your smaller circle to be the center of the larger circle.  It has been a while since I last worked with expression controllers but they are not that hard once you get them started. 

Darv

Darvin Atkeson
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http://LiquidMoonlight.com
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Hey there, not sure if this will help.

One way would be to use Parameter Wiring. Open the Parameter Wire window (Animation > Wire Parameters > Parameter Wire Dialog) on the left panel navigate to your big circle’s Z Rotation (or what ever axis you are using) and highlight it. On the right side navigate to your small circle’s Z Rotation and highlight that as well. Choose the control direction arrow, in your case the arrow that points to your small circle you want to be slower. Now before you hit Connect, in the small circles Expression for Z_Rotation window you can divide it by a number. Just append /2, /5 or what ever you wish the rotation to be. You can have your small circle anywhere in the scene and be animated. While the rotation speed will be affected by the larger one divided by what ever you want.

Not sure if this will work for your scene but I hope it helps.

Cheers.

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Sorry I think I miss read your post and gave you some wrong info. You could create a dummy centered with the large circle and perform the Parameter Wire as I posted above to make the dummy rotate slower. Then link your small circle to the dummy. SO this way you have your pivots intact and can still animate the small circle. I edited this post to re iterate what Valen Wagner said.

It’s my understanding that you want the small circle to rotate around the center of the big circle, but you want the small circle’s pivot to still remain at it’s center.  You can create a dummy at the center of the big circle.  Wire the dummys rotation as half that of the big circle.  Then link the small circle to the dummy.  Now the small circle’s position will “rotate” around the big circle at the rate of the dummy.

3ds Max 2013, Maya 2013
Windows 7 Ultimate 64 Bit
Core i7, 12GB RAM
Nvidia Quadro FX 3700 (Driver 267.17)

Couldn’t see the wood for the trees.

Cheers for that Valen (and others), much appreciated!