The Physics Manager lets you provide global settings for 3D physics (menu: ). There is also a corresponding manager for 2D physics, described here.
|Gravity||The amount of gravity applied to all Rigidbodies. Usually gravity acts only on the Y-axis (negative is down). Gravity is world units per second squared. Note: Increasing the gravity might require increasing the “Solver Iteration Count” to maintain stable contacts.|
|Default Material||The default Physics Material that will be used if none has been assigned to an individual Collider.|
|Bounce Threshold||Two colliding objects with a relative velocity below this value will not bounce. This value also reduces jitter so it is not recommended to set it to a very low value.|
|Sleep Velocity||The default linear velocity, below which objects start going to sleep.|
|Max Angular Velocity||The default maximimum angular velocity permitted for any Rigidbodies. The angular velocity of Rigidbodies is clamped to stay within Max Angular Velocity to avoid numerical instability with quickly rotating bodies. Because this may prevent intentional fast rotations on objects such as wheels, you can override this value for any Rigidbody by scripting Rigidbody.maxAngularVelocity.|
|Min Penetration For Penalty||How deep in meters are two objects allowed to penetrate before the collision solver pushes them apart. A higher value will make objects penetrate more but reduces jitter.|
|Solver Iteration Count||Determines how accurately joints and contacts are resolved. Usually a value of 7 works very well for almost all situations.|
|Raycasts Hit Triggers||If enabled, any Raycast that intersects with a Collider marked as a Trigger will return a hit. If disabled, these intersections will not return a hit.|
|Enable Adaptive Force||The “adaptive force” affects the way forces are transmitted through a pile or stack of objects with the aim of giving more realistic behaviour. This option enables or disables the adaptive force. Note that from Unity 5.0, this is disabled by default.|
|Layer Collision Matrix||Defines how the layer-based collision detection system will behave.|
The settings of the physics manager define limits on the accuracy of the physical simulation. Generally speaking, a more accurate simulation requires more processing overhead, so these settings offer a way to trade off accuracy against performance. See the Physics section of the manual for further information.