A body is contained within a world and has 3 degrees-of-freedom, two for position and one for rotation. A body can have forces, torques and impulses applied to it. A body has three distinct types:
| Property | Description |
|---|---|
| angularDamping | The angular damping of the body. This will reduce the angular velocity over time. See PhysicsBody.angularVelocity. |
| angularVelocity | The angular velocity of the body. |
| awake | The awake state of the body. |
| bodyConstraints | Get/Set the degrees of freedom constraints (locks) for the body of Linear X, Linear Y and Rotation Z. |
| bodyType | A body is one of these three body types, Dynamic, Kinematic or Static, each of which determines how the body behaves in the simulation. |
| callbackTarget | Get/Set the UnityEngine.MonoBehaviour that event callbacks for this body will be sent to. This includes the following events: - A BodyUpdateEvent with call IBodyUpdateCallback. |
| definition | Get/Set a body definition by accessing all of its properties. This is provided as convenience only and should not be used when performance is important as all the properties defined in the definition are accessed sequentially. You should try to only use the specific properties you need rather than using this feature. |
| enabled | The enabled state of the body. If false, the body and anything attached to it will not participate in the simulation. |
| fastCollisionsAllowed | Treat this body as high speed object that performs continuous collision detection against dynamic and kinematic bodies, but not other high speed bodies. Fast collision bodies should be used sparingly. They are not a solution for general dynamic-versus-dynamic continuous collision. |
| fastRotationAllowed | This allows this body to bypass rotational speed limits. This should only be used for circular objects, such as wheels, balls etc. |
| gravityScale | Scales the world gravity that is applied to this body. Setting the gravity scale to zero stops any gravity being applied. Likewise, a negative value inverts gravity. See PhysicsWorld.gravity. |
| isOwned | Get if the body is owned. See PhysicsBody.SetOwner. |
| isValid | Checks if a body is valid. |
| jointCount | Get the number of joints attached to this body. Use PhysicsBody.GetJoints to retrieve the joints. |
| linearDamping | The linear damping of the body. This will reduce the linear velocity over time. See PhysicsBody.linearVelocity. |
| linearVelocity | The linear velocity of the body. |
| localCenterOfMass | The center of mass position of the body in local space. |
| mass | The calculated mass of the body, usually in kilograms. See PhysicsBody.massConfiguration. |
| massConfiguration | The body mass configuration. Normally this is computed automatically using the shape geometry and density. This information changes if a shape is added or removed or if the body type changes. See MassConfiguration. |
| position | The position of the body in the world. |
| rotation | The rotation of the body. |
| rotationalInertia | The rotational inertia of the body, usually in kg*m^2. See PhysicsBody.massConfiguration. |
| shapeCount | Get the number of shapes attached to this body. Use PhysicsBody.GetShapes to retrieve the shapes. |
| sleepingAllowed | The sleeping ability of the body. If false, the body will never sleep and will be woken up. See PhysicsBody.awake. |
| sleepThreshold | The threshold below which the body will sleep, usually in m/s. |
| transform | The full transform of the body composed of position and rotation. |
| transformObject | Get/Set the transform object associated with the body. This can be used as a write transform and/or as a hint for debug drawing. See PhysicsBody.transformWriteMode. |
| transformWriteMode | Get/Set how the PhysicsBody.transformObject should be written to after the simulation has completed. Transform write will only occur if it is enabled on the world using PhysicsWorld.transformWriteMode. |
| userData | Get/Set PhysicsUserData that can be used for any purpose. The physics system doesn't use this data, it is entirely for custom use. |
| world | Get the world the body is attached to. |
| worldCenterOfMass | The center of mass position of the body in world space. |
| Method | Description |
|---|---|
| ApplyAngularImpulse | Apply an angular impulse. This should be used for one-shot impulses. If you need a steady torque, use a torque instead, which will work better with the sub-stepping solver. |
| ApplyForce | Apply a force at a world point. If the force is not applied at the center of mass, it will generate a torque and affect the angular velocity. |
| ApplyForceToCenter | Apply a force to the center of mass. |
| ApplyLinearImpulse | Apply an impulse at a point. This immediately modifies the velocity and also modifies the angular velocity if the point of application is not at the center of mass. This should be used for one-shot impulses. If you need a steady force, use a force instead, which will work better with the sub-stepping solver. |
| ApplyLinearImpulseToCenter | Apply an impulse to the center of mass. This immediately modifies the velocity. This should be used for one-shot impulses. If you need a steady force, use a force instead, which will work better with the sub-stepping solver. |
| ApplyMassFromShapes | This updates the mass configuration to the sum of the mass configuration of all the attached shapes. This normally does not need to be called unless you set the mass configuration to override the mass and you later want to reset the mass. You should call this regardless of body type. Note that sensor shapes may have mass. |
| ApplyTorque | Apply a torque. This affects the angular velocity without affecting the linear velocity. |
| CreateChain | Create a Chain attached to this body. |
| CreateShape | Create a Circle shape, using its default definition, attached to this body. |
| CreateShapeBatch | Create a batch of Circle shapes attached to this body. |
| Destroy | Destroy a body, destroying all attached PhysicsShape and PhysicsJoint. If the object is owned with PhysicsBody.SetOwner then you must provide the owner key it returned. Failing to do so will return a warning and the body will not be destroyed. |
| Draw | Draw a body that visually represents its current state in the world. This is only used in the Unity Editor or in a Development Player. See LowLevelPhysics2D.PhysicsWorld.DrawResults, PhysicsWorld.drawOptions and LowLevelPhysics2D.PhysicsWorld.drawResults. |
| GetAABB | Get the world AABB that bounds all the shapes attached to this body. If there are no shapes attached to the body then the returned AABB is empty and centered on the body origin. |
| GetContacts | Get all the touching contacts this body is currently participating in. Speculative collision is used so some contact points may be separated, a property available in the provided contact manifold. |
| GetJoints | Get the joints attached to this body. |
| GetLocalPoint | Gets a local point relative to the body given a world point. |
| GetLocalPointVelocity | Get the linear velocity of a local point attached to a body. Usually in meters per second. |
| GetLocalVector | Gets a local vector on a body given a world vector. |
| GetOwner | Get the owner object associated with this body as specified using PhysicsBody.SetOwner. |
| GetPositionAndRotation3D | Get the full 3D position and rotation of the body given the specified TransformWriteMode and TransformPlane. Usually both the write-mode and transform-plane of the world the body is in would be used. This can only be called when a PhysicsBody.transformObject is assigned. Without this, an exception is thrown. See PhysicsWorld.transformWriteMode and PhysicsWorld.transformPlane. |
| GetShapes | Get the shapes attached to this body. |
| GetWorldPoint | Gets a world point transformed from a local point relative to the body. |
| GetWorldPointVelocity | Get the linear velocity of a world point attached to a body. Usually in meters per second. |
| GetWorldVector | Gets a world vector transformed from a local vector relative to the body. |
| SetAndWriteTransform | Set the full transform of the body composed of position and rotation and also write to the associated PhysicsBody.transformObject. The PhysicsBody.transformObject won't be written to if it isn't assigned or the PhysicsWorld.transformWriteMode are off. The body will always be updated however. See PhysicsBody.transformObject. |
| SetContactEvents | Enable/disable contact events on all shapes attached to the body. See PhysicsShape.contactEvents. |
| SetHitEvents | Enable/disable hit events on all shapes attached to the body. See PhysicsShape.hitEvents. |
| SetOwner | Set the (optional) owner object associated with this body and return an owner key that must be specified when destroying the body with PhysicsBody.Destroy. The physics system provides access to all objects, including the ability to destroy them so this feature can be used to stop accidental destruction of objects that are owned by other objects. You can only set the owner once, multiple attempts will produce a warning. The lifetime of the specified owner object is not linked to this body i.e. this body will still be owned by the owner object, even if it is destroyed. It is also valid to not specify an owner object (NULL) to simply gain an owner key however it can be useful, if simply for debugging purposes and discovery, to know which object is the owner. |
| SetTransformTarget | Set the PhysicsBody.linearVelocity and PhysicsBody.angularVelocity to reach the specified transform in the specified time. The resultant transform will be closed by may not be exact. This is designed ideally for Kinematic bodies but will work with Dynamic bodies if nothing changes the assigned velocities. This will be ignored if the calculated PhysicsBody.linearVelocity and PhysicsBody.angularVelocity would be below the PhysicsBody.sleepThreshold. This will automatically wake the body if it is asleep. |
| Method | Description |
|---|---|
| Create | Create a body using PhysicsBodyDefinition.defaultDefinition in the specified world. |
| CreateBatch | Create a batch of bodies in the specified world. |
| DestroyBatch | Destroy a batch of bodies, destroying all attached PhysicsShape and PhysicsJoint. Any invalid bodies will be ignored. Owned bodies will produce a warning and will not be destroyed (See PhysicsBody.SetOwner). |
| SetBatchForce | Apply a force for a batch of PhysicsBody using a span of BatchForce. If invalid values are passed to the batch, they will simply be ignored. For best performance, the bodies contained in the batch should all be part of the same PhysicsWorld. If the bodies in the batch are not contained in the same PhysicsWorld, the batch should be sorted by the PhysicsWorld the bodies are contained within. |
| SetBatchImpulse | Applu an impulse for a batch of PhysicsBody using a span of BatchImpulse. If invalid values are passed to the batch, they will simply be ignored. For best performance, the bodies contained in the batch should all be part of the same PhysicsWorld. If the bodies in the batch are not contained in the same PhysicsWorld, the batch should be sorted by the PhysicsWorld the bodies are contained within. |
| SetBatchTransform | Set the transform for a batch of PhysicsBody using a span of BatchTransform. If invalid values are passed to the batch, they will simply be ignored. For best performance, the bodies contained in the batch should all be part of the same PhysicsWorld. If the bodies in the batch are not contained in the same PhysicsWorld, the batch should be sorted by the PhysicsWorld the bodies are contained within. |
| SetBatchVelocity | Set the velocity for a batch of PhysicsBody using a span of BatchVelocity. If invalid values are passed to the batch, they will simply be ignored. For best performance, the bodies contained in the batch should all be part of the same PhysicsWorld. If the bodies in the batch are not contained in the same PhysicsWorld, the batch should be sorted by the PhysicsWorld the bodies are contained within. |