Object must only rotate Clockwise

Support Animation and Rigging
#1

I am trying to animate a gear assembly which is on a one way clutch. Other parts of the machine are always turning, however this portion must be limited to clockwise rotation. This is kind like the sprocket on a bicycle, even though the wheels can turn any direction, the sprocket only turns when force is applied to the pedals, and even then only in one direction.

I thought about using the limit rotation constraint but there I must define a min and max limit for rotation. Is there a better way to limit the rotation to only positive values?

#2

So I guess in simple terms I am looking for a way to constrict the rotation of one element to clockwise rotation only. Basically when its parent spins clockwise it will copy rotation, howver when the parent is spinning CCW the locked element will be stationary.

Any ideas on how to do this?

#3

Ooh, I don’t think there is a way other than manually. Blender’s animation system considers each frame independently of anything around it; it knows nothing of objects’ velocities or accelerations, linear or angular. This is a problem because, to constrain an object to only rotate clockwise (or never move in the negative x-direction, only positive, or only get larger, never smaller,) the state of the object immediately before is a required input, and as of now, we can’t get that.