HingeJoint

This component creates a hinge joint.

Two objects, node0 and node1, will lose all but a single degree of freedom: they can now only rotate around the X-axis of the node that contains this component. The rotation can also be constrained by the angle parameter around the Y-axis. For example, angle = 15. would allow the bodies to rotate between -15 and +15 degrees, where the Y-axis of the joint represents 0.

This joint can be used to make doors, fans, and even simulate a 2D ball-and-swing joint.

The joint can be added as a component to either one of the two bodies, or to a new entity with a single joint component — the behavior of the joint is the same either way.

Only one joint can be added to a single node.

This component is provided by the engine.physics_core module, which is included in the engine.core module.

Example:

require engine.core

// Create first body
let nodeA = create_node(NodeData(position = float3(0, 10, 10), scale = float3(1, 1, 10)))
add_component(nodeA, new RigidBody())
add_component(nodeA, new BoxCollider())

// Create second body
let nodeB = create_node(NodeData(position = float3(0, 10, -10), scale = float3(1, 1, 10)))
add_component(nodeB, new RigidBody())
add_component(nodeB, new BoxCollider())

// Create joint that keeps two bodies at the distance they were created at - 20
add_component(create_node(NodeData(position = float3(0, 10, 0))), new HingeJoint(
    node0 = nodeA,
    node1 = nodeB,
    angle = 45.
))

Classes

HingeJoint : NativeComponent

A simple hinge joint. Rotate second body around first (or vise versa).

Properties:

HingeJoint.node0: NodeId
HingeJoint.node0 =(value: NodeId)

A first body of the joint. It should have an active RigidBody component.

Arguments:
HingeJoint.node1: NodeId
HingeJoint.node1 =(value: NodeId)

A second body of the joint. It should have an active RigidBody component.

Arguments:
HingeJoint.allowCollision: bool
HingeJoint.allowCollision =(value: bool)

Used for disabling collision between the joined bodies. Default is false, disables collision.

Arguments:

  • value : bool

HingeJoint.angle: float
HingeJoint.angle =(value: float)

Allowed rotation around local Y axis of the node

Arguments:

  • value : float

HingeJoint.frictionTorque: float
HingeJoint.frictionTorque =(value: float)

Maximum amount of torque to apply as friction

Arguments:

  • value : float

HingeJoint.softLimit: float2
HingeJoint.softLimit =(value: float2)

Soft limit. When the angle goes out of bounds, the soft limits can pull it back with a spring force. The spring settings are packed to float2 where x is a spring frequency in Hz, and y is a spring damping (0 = no damping, 1 = critical damping, >1 = overdamp). If frequency = 0, the soft limit is disabled and the constraint will have hard limits.

Arguments:

  • value : float2