@modoki/engine / index / Joint2D

Variable: Joint2D

const Joint2D: Trait<{ anchorAX: number; anchorAY: number; anchorBX: number; anchorBY: number; axisX: number; axisY: number; damping: number; entityA: string; entityB: string; length: number; limitMax: number; limitMin: number; limitsEnabled: boolean; motorDamping: number; motorEnabled: boolean; motorStiffness: number; motorTargetPos: number; motorTargetVel: number; stiffness: number; type: JointType2D; }>

A constraint between two RigidBody2D entities. Attach Joint2D to a THIRD entity (or either body) — it is not a body itself, just a link record. entityA/ entityB are GUIDs (like BoneAttachment.target); the joint activates once both resolve to bodies. Anchors are local offsets (world units) on each body.

Unit notes (converted to Rapier's frame by physics2DJoints):

• anchors/axis: world units, Y-down (flipped like Transform).
• length: world units (spring rest / rope max).
• revolute motor/limit values are ANGLES (radians); prismatic ones are DISTANCES (world units) along the axis.