# Built-in 3D physics

> Use this integration of the Nvidia PhysX engine in object-oriented 3D projects.

Unity's default built-in 3D physics system is an integration of the Nvidia PhysX engine. You can use this system in object-oriented 3D projects.

This section includes the following topics.

| **Topic**                                                                                                                   | **Description**                                                                                                           |
| --------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| **[Character control](/engine/6000.7/manual/physics-section/physics-overview/character-control-section.md)**                | Configure physics-based character control for first-person and third-person characters.                                   |
| **[Rigidbody physics](/engine/6000.7/manual/physics-section/physics-overview/rigidbody.md)**                                | Apply physics-based behavior to GameObjects.                                                                              |
| **[Collision](/engine/6000.7/manual/physics-section/physics-overview/collision-section.md)**                                | Use colliders to configure collisions between GameObjects.                                                                |
| **[Joints](/engine/6000.7/manual/physics-section/physics-overview/joints-section.md)**                                      | Apply and configure joints that connect GameObjects and simulate physical forces for pivoting, movement, and restriction. |
| **[Articulations](/engine/6000.7/manual/physics-section/physics-overview/articulations-section.md)**                        | Configure complex systems of rigid bodies and joints.                                                                     |
| **[Ragdoll physics](/engine/6000.7/manual/physics-section/physics-overview/ragdoll.md)**                                    | Configure ragdoll physics for characters.                                                                                 |
| **[Optimize physics performance](/engine/6000.7/manual/physics-section/physics-overview/physics-optimization.md)**          | Optimize physics system performance in the Unity Editor.                                                                  |
| **[Cloth](/engine/6000.7/manual/physics-section/physics-overview/class-cloth.md)**                                          | Simulate fabric movement for character clothing and other in-application textiles.                                        |
| **[Multi-scene physics](/engine/6000.7/manual/physics-section/physics-overview/physics-multi-scene.md)**                    | Manage different physics contexts in one project with multiple dedicated physics scenes.                                  |
| **[Physics Debug window reference](/engine/6000.7/manual/physics-section/physics-overview/physics-debug-visualization.md)** | Use the Physics Debug window to configure and generate visual representations of 3D physics activity in a scene.          |
| **[Physics Profiler module](/engine/6000.7/manual/physics-section/physics-overview/profiler-physics.md)**                   | Analyze the performance of physics in your application.                                                                   |

## Additional resources

* [World building](/engine/6000.7/manual/creating-environments.md)
* [2D Physics](/engine/6000.7/manual/unity2d/2d-physics.md)
* [Managing time and frame rate](/engine/6000.7/manual/scripting/managing-time-and-frame-rate.md)