Hello, I've had issues with a workflow where I have motion capture data on a layer that I'm trying to track to a multi-layered/pinned puppet.
I have the multi-layered puppet set in the position I want in AE, I placed 2 puppet pins per limb, and put in the first expression code for each layer to link to null objects for corresponding parts (ie LeftFoot, LeftLowerLeg, LeftUpperLeg linked to the LeftLeg Null), I have those directed to Point Controls in the nulls, and then I have an expression on all the nulls for Point Controls to track to the motion control data.
Everything is working great except when I put the expression for the point controls to link to the motion control layer, it changes the origin of each layer (ie the LeftFoot, etc) to the far left of my screen. The only way to bring it back in place is to change the anchor point and position values of the nulls manually. but I'm going off an AE file where this was done successfully without moving the nulls. It starts to warp things in the motion when I move the nulls around so hopefully there's a way to tell the expression in the nulls to keep the origin of the original object position. See below for the expressions (everything reflects those 2 examples from the objects to the nulls).
Just to follow up on this post, it was a resolution translation issue: I was tracking mocap data recorded in SD space and trying to track it in an HD comp which made all the points change (especially with the expressions). The solution was to precomp the footage in SD, then bring it into an HD comp and then upscale the SD precomp.