RigidBody

Inherits: PhysicsBody < CollisionObject < Spatial < Node < Object

Inherited By: VehicleBody

Physics Body whose position is determined through physics simulation in 3D space.

Description

This is the node that implements full 3D physics. This means that you do not control a RigidBody directly. Instead, you can apply forces to it (gravity, impulses, etc.), and the physics simulation will calculate the resulting movement, collision, bouncing, rotating, etc.

A RigidBody has 4 behavior modes: Rigid, Static, Character, and Kinematic.

Note: Don’t change a RigidBody’s position every frame or very often. Sporadic changes work fine, but physics runs at a different granularity (fixed Hz) than usual rendering (process callback) and maybe even in a separate thread, so changing this from a process loop may result in strange behavior. If you need to directly affect the body’s state, use _integrate_forces, which allows you to directly access the physics state.

If you need to override the default physics behavior, you can write a custom force integration function. See custom_integrator.

With Bullet physics (the default), the center of mass is the RigidBody3D center. With GodotPhysics, the center of mass is the average of the CollisionShape centers.

Tutorials

• Physics introduction

• 3D Truck Town Demo

• 3D Physics Tests Demo

Properties

Methods

Signals

• body_entered ( Node body )

Emitted when a collision with another PhysicsBody or GridMap occurs. Requires contact_monitor to be set to true and contacts_reported to be set high enough to detect all the collisions. GridMaps are detected if the MeshLibrary has Collision Shapes.

body the Node, if it exists in the tree, of the other PhysicsBody or GridMap.

• body_exited ( Node body )

Emitted when the collision with another PhysicsBody or GridMap ends. Requires contact_monitor to be set to true and contacts_reported to be set high enough to detect all the collisions. GridMaps are detected if the MeshLibrary has Collision Shapes.

body the Node, if it exists in the tree, of the other PhysicsBody or GridMap.

• body_shape_entered ( RID body_rid, Node body, int body_shape_index, int local_shape_index )

Emitted when one of this RigidBody’s Shapes collides with another PhysicsBody or GridMap‘s Shapes. Requires contact_monitor to be set to true and contacts_reported to be set high enough to detect all the collisions. GridMaps are detected if the MeshLibrary has Collision Shapes.

body_rid the RID of the other PhysicsBody or MeshLibrary‘s CollisionObject used by the PhysicsServer.

body the Node, if it exists in the tree, of the other PhysicsBody or GridMap.

body_shape_index the index of the Shape of the other PhysicsBody or GridMap used by the PhysicsServer. Get the CollisionShape node with body.shape_owner_get_owner(body_shape_index).

local_shape_index the index of the Shape of this RigidBody used by the PhysicsServer. Get the CollisionShape node with self.shape_owner_get_owner(local_shape_index).

Note: Bullet physics cannot identify the shape index when using a ConcavePolygonShape. Don’t use multiple CollisionShapes when using a ConcavePolygonShape with Bullet physics if you need shape indices.

• body_shape_exited ( RID body_rid, Node body, int body_shape_index, int local_shape_index )

Emitted when the collision between one of this RigidBody’s Shapes and another PhysicsBody or GridMap‘s Shapes ends. Requires contact_monitor to be set to true and contacts_reported to be set high enough to detect all the collisions. GridMaps are detected if the MeshLibrary has Collision Shapes.

body_rid the RID of the other PhysicsBody or MeshLibrary‘s CollisionObject used by the PhysicsServer. GridMaps are detected if the Meshes have Shapes.

body the Node, if it exists in the tree, of the other PhysicsBody or GridMap.

body_shape_index the index of the Shape of the other PhysicsBody or GridMap used by the PhysicsServer. Get the CollisionShape node with body.shape_owner_get_owner(body_shape_index).

local_shape_index the index of the Shape of this RigidBody used by the PhysicsServer. Get the CollisionShape node with self.shape_owner_get_owner(local_shape_index).

Note: Bullet physics cannot identify the shape index when using a ConcavePolygonShape. Don’t use multiple CollisionShapes when using a ConcavePolygonShape with Bullet physics if you need shape indices.

• sleeping_state_changed ( )

Emitted when the physics engine changes the body’s sleeping state.

Note: Changing the value sleeping will not trigger this signal. It is only emitted if the sleeping state is changed by the physics engine or emit_signal("sleeping_state_changed") is used.

Enumerations

enum Mode:

• MODE_RIGID = 0 —- Rigid body mode. This is the “natural” state of a rigid body. It is affected by forces, and can move, rotate, and be affected by user code.

• MODE_STATIC = 1 —- Static mode. The body behaves like a StaticBody, and can only move by user code.

• MODE_CHARACTER = 2 —- Character body mode. This behaves like a rigid body, but can not rotate.

• MODE_KINEMATIC = 3 —- Kinematic body mode. The body behaves like a KinematicBody, and can only move by user code.

Property Descriptions

• float angular_damp

Damps the body’s rotational forces. If this value is different from -1.0 it will be added to any angular damp derived from the world or areas.

See ProjectSettings.physics/3d/default_angular_damp for more details about damping.

• Vector3 angular_velocity

The body’s rotational velocity in axis-angle format. The magnitude of the vector is the rotation rate in radians per second.

• bool axis_lock_angular_x

Lock the body’s rotation in the X axis.

• bool axis_lock_angular_y

Lock the body’s rotation in the Y axis.

• bool axis_lock_angular_z

Lock the body’s rotation in the Z axis.

• bool axis_lock_linear_x

Lock the body’s movement in the X axis.

• bool axis_lock_linear_y

Lock the body’s movement in the Y axis.

• bool axis_lock_linear_z

Lock the body’s movement in the Z axis.

• float bounce

The body’s bounciness. Values range from 0 (no bounce) to 1 (full bounciness).

Deprecated, use PhysicsMaterial.bounce instead via physics_material_override.

• bool can_sleep

If true, the body can enter sleep mode when there is no movement. See sleeping.

Note: A RigidBody3D will never enter sleep mode automatically if its mode is MODE_CHARACTER. It can still be put to sleep manually by setting its sleeping property to true.

• bool contact_monitor

If true, the RigidBody will emit signals when it collides with another RigidBody. See also contacts_reported.

• int contacts_reported

The maximum number of contacts that will be recorded. Requires contact_monitor to be set to true.

Note: The number of contacts is different from the number of collisions. Collisions between parallel edges will result in two contacts (one at each end), and collisions between parallel faces will result in four contacts (one at each corner).

• bool continuous_cd

If true, continuous collision detection is used.

Continuous collision detection tries to predict where a moving body will collide, instead of moving it and correcting its movement if it collided. Continuous collision detection is more precise, and misses fewer impacts by small, fast-moving objects. Not using continuous collision detection is faster to compute, but can miss small, fast-moving objects.

• bool custom_integrator

If true, internal force integration will be disabled (like gravity or air friction) for this body. Other than collision response, the body will only move as determined by the _integrate_forces function, if defined.

• float friction

The body’s friction, from 0 (frictionless) to 1 (max friction).

Deprecated, use PhysicsMaterial.friction instead via physics_material_override.

• float gravity_scale

This is multiplied by the global 3D gravity setting found in Project > Project Settings > Physics > 3d to produce RigidBody’s gravity. For example, a value of 1 will be normal gravity, 2 will apply double gravity, and 0.5 will apply half gravity to this object.

• float linear_damp

The body’s linear damp. Cannot be less than -1.0. If this value is different from -1.0 it will be added to any linear damp derived from the world or areas.

See ProjectSettings.physics/3d/default_linear_damp for more details about damping.

• Vector3 linear_velocity

The body’s linear velocity in units per second. Can be used sporadically, but don’t set this every frame, because physics may run in another thread and runs at a different granularity. Use _integrate_forces as your process loop for precise control of the body state.

• float mass

The body’s mass.

• Mode mode

The body mode. See Mode for possible values.

• PhysicsMaterial physics_material_override

The physics material override for the body.

If a material is assigned to this property, it will be used instead of any other physics material, such as an inherited one.

• bool sleeping

If true, the body will not move and will not calculate forces until woken up by another body through, for example, a collision, or by using the apply_impulse or add_force methods.

• float weight

The body’s weight based on its mass and the global 3D gravity. Global values are set in Project > Project Settings > Physics > 3d.

Method Descriptions

• void _integrate_forces ( PhysicsDirectBodyState state ) virtual

Called during physics processing, allowing you to read and safely modify the simulation state for the object. By default, it works in addition to the usual physics behavior, but the custom_integrator property allows you to disable the default behavior and do fully custom force integration for a body.

• void add_central_force ( Vector3 force )

Adds a constant directional force (i.e. acceleration) without affecting rotation.

This is equivalent to add_force(force, Vector3(0,0,0)).

• void add_force ( Vector3 force, Vector3 position )

Adds a constant directional force (i.e. acceleration).

The position uses the rotation of the global coordinate system, but is centered at the object’s origin.

• void add_torque ( Vector3 torque )

Adds a constant rotational force (i.e. a motor) without affecting position.

• void apply_central_impulse ( Vector3 impulse )

Applies a directional impulse without affecting rotation.

This is equivalent to apply_impulse(Vector3(0,0,0), impulse).

• void apply_impulse ( Vector3 position, Vector3 impulse )

Applies a positioned impulse to the body. An impulse is time independent! Applying an impulse every frame would result in a framerate-dependent force. For this reason it should only be used when simulating one-time impacts. The position uses the rotation of the global coordinate system, but is centered at the object’s origin.

• void apply_torque_impulse ( Vector3 impulse )

Applies a torque impulse which will be affected by the body mass and shape. This will rotate the body around the impulse vector passed.

• bool get_axis_lock ( BodyAxis axis ) const

Returns true if the specified linear or rotational axis is locked.

• Array get_colliding_bodies ( ) const

Returns a list of the bodies colliding with this one. Requires contact_monitor to be set to true and contacts_reported to be set high enough to detect all the collisions.

Note: The result of this test is not immediate after moving objects. For performance, list of collisions is updated once per frame and before the physics step. Consider using signals instead.

• Basis get_inverse_inertia_tensor ( )

Returns the inverse inertia tensor basis. This is used to calculate the angular acceleration resulting from a torque applied to the RigidBody.

• void set_axis_lock ( BodyAxis axis, bool lock )

Locks the specified linear or rotational axis.

• void set_axis_velocity ( Vector3 axis_velocity )

Sets an axis velocity. The velocity in the given vector axis will be set as the given vector length. This is useful for jumping behavior.