HELP: motion path + constraint = flipping

#1

Hello :slight_smile:

I have some trouble with a motion path. I have a locator1 and a curvy path, the locator1 is motionpathed on the curve, with follow mode, World Up Type = Vector 0-1-0, Front = Z and Up = Y.

Then, I have a locator2 that is ParentConstrained to the locator1, with All Transforms but only side Rotate ( Y ).

The problem is that, when the path become curvy, the locator1 stays on the path nicely, but the locator2 flips.

Here are some screenshots to help you visualize the monster. Locator1 = on the curve, Locator2 = pink one

Then, I move in the time a little bit, so the Locator1 can move forward:

Is there a way to fix this problem? I know there is the Twists options on the MP, but they do not really help and I don’t want to take hours to key this parameters.

EDIT: After some deep research, the problem is that the Locator1 is gimballed the messy way. When I bake the animation and open the GraphEditor:

Is there a way to fix this without destroying everything ?

Thank you very much !:blush:

#2

Try this:
Looking at the baked curves in the graph editor.
Select all of the keys
On the menu curves pick euler filter.

#3

Thanks !

But the thing is that I don’t want a baked animcurve, I need to keep my locator constrained to the MP. That way I can edit my path when I want to.

After a lot of testing, I’ve found a workaround. The main problem is that when a motionPath is on Follow mode, the rotateOrder is locked on xyz, even if you change it before. You can unlock it, but the only thing you’ll find is pain :smiley:

So, I tried to create a locator3.
The locator1 is still on motionPath, but NO FOLLOW.
The locator3 is on the same mP, but in right in front of the 1 ( Uvalue offseted by 1 frame ) , with FOLLOW.
Then I did a aim constrain loc1 > loc3. The aim constrain does not block the rotateOrder attribute.
So I switched it to xzy for locators 1 and 2 and voila :stuck_out_tongue:

It works very well. I’m just disappointed that I had to do all this rig. A simple solution should be implemented in Maya…

Thanks anyway !