The physics system contains a series of Joint components for linking two rigidbodies. Joint components can be used to simulate the interaction between real objects, such as hinges, pistons, ropes, wheels, pulleys, motor vehicles, chains and so on. Learning how to use joint components can effectively help create a truly interesting scene.

The following joints are available in the physics system:

Common properties of joints

Although each joint has a different behavior, they have some common properties.

Each joint need to link two rigidbodies to work. The one on the same node of the joint and the one on another node, which will be assigned to connectedBody property.

Normally, each rigidbody will set this point around its surrounding position. Depending on the type of joint component, this determines the axis of rotation of the object, or the coordinate point used to maintain a certain distance, and so on.

collideConnected property allows you to decide whether the rigidbody at both ends of the joint needs to continue to follow conventional collision rules. For example, if you are now ready to make a ragdoll, you may want the upper and lower leg can be partially intersected, and then linked at the knee joint. You will need to set collideConnected property to false. If you are making a lift, you may want the lift platform and floor to collide, then you need to set the collideConnected property to true.