---
title: Physics joints and pins
framework: realitykit
role: collectionGroup
role_heading: API Collection
path: realitykit/physics-joints-and-pins
---

# Physics joints and pins

Simulate joint physics that connect virtual objects.

## Overview

Overview In a 3D environment, you can animate various attributes of an Entity such as its location, rotation, and size from one value to another. This is ideal for simple pre-defined motion, but does not allow for interaction with external forces, such as collisions with other objects, or gestures. With a PhysicsJoint you can connect entities with pins, and RealityKit keeps your entities bound by constraints that you define. Each joint consists of two pins, each of which belongs to a different entity. Each GeometricPin moves and rotates relative to each other within the bounds of the joint’s constraints.

## Topics

### Pin and joint components

- [Simulating physics joints in your RealityKit app](realitykit/simulating-physics-joints-in-your-realitykit-app.md)
- [GeometricPin](realitykit/geometricpin.md)
- [GeometricPinsComponent](realitykit/geometricpinscomponent.md)
- [PhysicsJoint](realitykit/physicsjoint.md)
- [PhysicsJointsComponent](realitykit/physicsjointscomponent.md)
- [EntityGeometricPins](realitykit/entitygeometricpins.md)
- [AttachedTransformComponent](realitykit/attachedtransformcomponent.md)

### Built-in joint types

- [PhysicsRevoluteJoint](realitykit/physicsrevolutejoint.md)
- [PhysicsPrismaticJoint](realitykit/physicsprismaticjoint.md)
- [PhysicsSphericalJoint](realitykit/physicssphericaljoint.md)
- [PhysicsCustomJoint](realitykit/physicscustomjoint.md)
- [PhysicsDistanceJoint](realitykit/physicsdistancejoint.md)
- [PhysicsFixedJoint](realitykit/physicsfixedjoint.md)
- [PhysicsJoints](realitykit/physicsjoints.md)

## See Also

### Physics simulation

- [Collision detection](realitykit/physics-collision-detection.md)
- [Simulations and motion](realitykit/physics-simulations-and-motion.md)
- [Force effects](realitykit/physics-force-effects.md)
- [Cloth simulation](realitykit/physics-cloth-simulation.md)