RigidBody2D

Inherits: PhysicsBody2D < CollisionObject2D < Node2D < CanvasItem < Node < Object

Category: Core

Brief Description

A body that is controlled by the 2D physics engine.

Member Functions

void _integrate_forces ( Physics2DDirectBodyState state ) virtual
void add_force ( Vector2 offset, Vector2 force )
void apply_impulse ( Vector2 offset, Vector2 impulse )
Vector2 get_applied_force ( ) const
float get_applied_torque ( ) const
Array get_colliding_bodies ( ) const
float get_inertia ( ) const
void set_applied_force ( Vector2 force )
void set_applied_torque ( float torque )
void set_axis_velocity ( Vector2 axis_velocity )
void set_inertia ( float inertia )
bool test_motion ( Vector2 motion, float margin=0.08, Physics2DTestMotionResult result=null )

Signals

  • body_entered ( Object body )

Emitted when a body enters into contact with this one. contact_monitor must be true and contacts_reported greater than 0.

Emitted when a body exits contact with this one. contact_monitor must be true and contacts_reported greater than 0.

  • body_shape_entered ( int body_id, Object body, int body_shape, int local_shape )

Emitted when a body enters into contact with this one. Reports colliding shape information. See CollisionObject2D for shape index information. contact_monitor must be true and contacts_reported greater than 0.

  • body_shape_exited ( int body_id, Object body, int body_shape, int local_shape )

Emitted when a body shape exits contact with this one. Reports colliding shape information. See CollisionObject2D for shape index information. contact_monitor must be true and contacts_reported greater than 0.

  • sleeping_state_changed ( )

Emitted when sleeping changes.

Member Variables

  • float angular_damp - Damps the body’s angular_velocity. If -1 the body will use the “Default Angular Damp” in “Project > Project Settings > Physics > 2d”. Default value: -1.
  • float angular_velocity - The body’s rotational velocity.
  • float bounce - The body’s bounciness. Default value: 0.
  • bool can_sleep - If true the body will not calculate forces and will act as a static body if there is no movement. The body will wake up when other forces are applied via collisions or by using apply_impulse or add_force. Default value: true.
  • bool contact_monitor - If true the body will emit signals when it collides with another RigidBody2D. See also contacts_reported. Default value: false.
  • int contacts_reported - The maximum number of contacts to report. Default value: 0.
  • int continuous_cd - Continuous collision detection mode. Default value: CCD_MODE_DISABLED.

Continuous collision detection tries to predict where a moving body will collide instead of moving it and correcting its movement after collision. Continuous collision detection is slower, but more precise and misses fewer collisions with small, fast-moving objects. Raycasting and shapecasting methods are available. See CCD_MODE\_ constants for details.

  • bool custom_integrator - If true internal force integration is disabled for this body. Aside from collision response, the body will only move as determined by the _integrate_forces function.
  • float friction - The body’s friction. Values range from 0 (frictionless) to 1 (maximum friction). Default value: 1.
  • float gravity_scale - Multiplies the gravity applied to the body. The body’s gravity is calculated from the “Default Gravity” value in “Project > Project Settings > Physics > 2d” and/or any additional gravity vector applied by Area2Ds. Default value: 1.
  • float linear_damp - Damps the body’s linear_velocity. If -1 the body will use the “Default Linear Damp” in “Project > Project Settings > Physics > 2d”. Default value: -1.
  • Vector2 linear_velocity - The body’s linear velocity.
  • float mass - The body’s mass. Default value: 1.
  • int mode - The body’s mode. See MODE\_\* constants. Default value: MODE_RIGID.
  • bool sleeping - If true the body is sleeping and will not calculate forces until woken up by a collision or by using apply_impulse or add_force.
  • float weight - The body’s weight based on its mass and the “Default Gravity” value in “Project > Project Settings > Physics > 2d”.

Numeric Constants

  • MODE_RIGID = 0 — Rigid mode. The body behaves as a physical object. It collides with other bodies and responds to forces applied to it. This is the default mode.
  • MODE_STATIC = 1 — Static mode. The body behaves like a StaticBody2D and does not move.
  • MODE_CHARACTER = 2 — Character mode. Similar to MODE_RIGID, but the body can not rotate.
  • MODE_KINEMATIC = 3 — Kinematic mode. The body behaves like a KinematicBody2D, and must be moved by code.
  • CCD_MODE_DISABLED = 0 — Continuous collision detection disabled. This is the fastest way to detect body collisions, but can miss small, fast-moving objects.
  • CCD_MODE_CAST_RAY = 1 — Continuous collision detection enabled using raycasting. This is faster than shapecasting but less precise.
  • CCD_MODE_CAST_SHAPE = 2 — Continuous collision detection enabled using shapecasting. This is the slowest CCD method and the most precise.

Description

This node implements simulated 2D physics. You do not control a RigidBody2D directly. Instead you apply forces to it (gravity, impulses, etc.) and the physics simulation calculates the resulting movement based on its mass, friction, and other physical properties.

A RigidBody2D has 4 behavior modes (see mode):

  • Rigid: The body behaves as a physical object. It collides with other bodies and responds to forces applied to it. This is the default mode.
  • Static: The body behaves like a StaticBody2D and does not move.
  • Character: Similar to Rigid mode, but the body can not rotate.
  • Kinematic: The body behaves like a KinematicBody2D, and must be moved by code.

Note: You should not change a RigidBody2D’s position or linear_velocity every frame or even very often. 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. See custom_integrator.

Member Function Description

Allows you to read and safely modify the simulation state for the object. Use this instead of Node._physics_process if you need to directly change the body’s position or other physics properties. By default it works in addition to the usual physics behavior, but custom_integrator allows you to disable the default behavior and write custom force integration for a body.

Adds a positioned force to the body. Both the force and the offset from the body origin are in global coordinates.

Applies a positioned impulse to the body (which will be affected by the body mass and shape). This is the equivalent of hitting a billiard ball with a cue: a force that is applied instantaneously. Both the impulse and the offset from the body origin are in global coordinates.

  • Vector2 get_applied_force ( ) const

Returns the body’s total applied force.

  • float get_applied_torque ( ) const

Returns the body’s total applied torque.

  • Array get_colliding_bodies ( ) const

Returns a list of the bodies colliding with this one. Use contacts_reported to set the maximum number reported. You must also set contact_monitor to true.

  • float get_inertia ( ) const

Returns the body’s moment of inertia, which is computed automatically from the body’s mass and assigned Shape2Ds during the physics frame. Note that it will not yet have a value in the _ready() function.

  • void set_applied_force ( Vector2 force )

Sets the applied force vector. This is the equivalent of firing a rocket: the force is applied constantly.

  • void set_applied_torque ( float torque )

Sets the applied torque.

  • void set_axis_velocity ( Vector2 axis_velocity )

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

  • void set_inertia ( float inertia )

Set the body’s moment of inertia. This is like mass, but for rotation: it determines how much torque it takes to rotate the body. The moment of inertia is usually computed automatically from the mass and the shapes, but this function allows you to set a custom value. Set 0 (or negative) inertia to return to automatically computing it.

Returns true if a collision would result from moving in the given vector. margin increases the size of the shapes involved in the collision detection, and result is an object of type Physics2DTestMotionResult, which contains additional information about the collision (should there be one).