Object Bond

Object bonds simulate how two objects can be put together (assembled, attached, glued) into a single rigid object. For example, screwing a bolt into a nut, or building structures using Lego-like pieces.

Each object can define, using XML, a number of bond points, each of which is a local location on the object that can be attached to another bond point on a different object. When two objects are attached, they act like a single rigid object in physics simulation. A bond point is either a host or a guest. Two bond points can be attached only if they have the same type string (a custom string) and that they are a host-guest pair. When attaching two bond points, the guest object (object having the guest bond point) will adjust its location and orientation in relation to those of the host bond point, while the host object remains still. Therefore, host bond points are typically defined on larger objects that do not move when a guest object is attached to them.