FollowJoint

What it does

FollowJoint builds no control. It point- and orient-constrains one joint to a source joint you pick in Properties, with independent per-axis skip and weight sliders for translate and rotate. It’s a plumbing component: useful wherever a joint just needs to track another one.

When to use it

• UE5 engine reference joints (ik_foot_*, ik_hand_*, ik_hand_gun) that need to follow their rig counterparts for export.
• Helper joints, prop attachers, or any joint that should track another without a control.
• As a placeholder in a template: leave the follow target empty and set it later, a supported no-op.

Good to know

• Leaving the follow target empty is silent, the joint doesn’t move, no warning printed.
• A follow target that doesn’t exist in the scene fails the build.
• Dropping either weight to 0, or turning off all axes on one side, skips building that constraint, so re-enabling it later needs a rebuild.
• Not mirrorable, and it never joins the FK/IK selection sets, since it has no control.