Constraining a rig's base control to the cog

[petermathes12]

Hello and thank you in advance,

I am moving my animation to Unreal. I need to move the base control with the body in order for the character to move properly in the engine. However, I didn't animate a cycle using the base layer. I have the cog driving the character's movement. Is there a way to constrain the base layer to the cog/body so they move together?

Here are reference videos:

Please let me know if you have any ideas! Thank you

[dinofiguera · Accepted solution]

create a locator,  point constraint this locator to the control that moves the character forward. In the point constraint option box, uncheck translate Y. This way the locator will only follow the x and Z translation.  
After the constraint, bake the locator´s animated channels so that you can remove the constraint.
Now that the locator moves by itself, you can delete the animation (translate x or z) of your cog controller and point constraint your main control to the locator (in the options, this time, check "maintain offset")
Now you can bake your main controller animation and remove the constraint.

[petermathes12]

Thank you! That explanation was very clear. The body is now working. However, the hands and feet are being dragged along. If I did the same thing using locators and point constraints would that fix them?

[dinofiguera]

I think I did not consider a few things, I was assuming you were using FK for your limbs.
With Ik yes, you have to bake locators for each limb,  then constraint your limbs to the baked locators but now you will have to use parent constraints (with maintain offset) instead of point constraints and leave all the axes checked since you want to grab the whole movement of your limbs...

to reassume:
go back to your working anim,  and bake locators for the cog and the limbs, the cog you only need the forward direction so you will use the limited point constraint, for the limbs you can use parent constraints.
once you bake all locators, you can now constrain the main control to the cog locator and parentconstraint the limbs to the locators. check if your animation works before baking your controls and remove constraints and locators...

[petermathes12]

Its working 🙂 Thank you!