Weld, WeldConstraint, Motor, and Motor6D all combine multiple parts into the same assembly. Every assembly has a root part (BasePart:GetRootPart()) and when C0/C1 of a JointInstance is modified, the root part will stay where it was.
Welds do not have any directionality. You can imagine rigid joints forming a tree branching down from the root part. All the parts down the tree from root will move, and their welded "children" in this tree will move with them.
This property determines if the joint is currently active in the world. If true, the joint is active.
Rigid joints like Weld, Snap, WeldConstraint, Motor, or Motor6D may also be disabled due to conflicts with other rigid joints, such as joints between the same two parts or indirect cycles in the weld graph. Joints disabled this way may be re-enabled later when another joint or part is added or removed.
This property sets whether the joint is active or not.
When this property is set to true, if the joints's JointInstance.Part0 and JointInstance.Part1 properties are set, then the joint will ensure that its two parts will be connected and behave according to joint type (e.g. Welds, and Snaps).
- JointInstance.Active, determines if the joint is currently active in the world