godot/doc/classes/RigidBody2D.xml
Corey Williams f19de2ae4c Add note about inertia being required for apply_torque on various Nodes
- RigidBody2D
  - PhysicsDirectBodyState2D
  - RigidBody3D
  - PhysicsDirectBodyState3D
2022-11-06 10:16:56 -05:00

286 lines
22 KiB
XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="RigidBody2D" inherits="PhysicsBody2D" version="4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
<brief_description>
Physics Body which is moved by 2D physics simulation. Useful for objects that have gravity and can be pushed by other objects.
</brief_description>
<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.
You can switch the body's behavior using [member lock_rotation], [member freeze], and [member freeze_mode].
[b]Note:[/b] You should not change a RigidBody2D's [code]position[/code] or [code]linear_velocity[/code] every frame or even very often. If you need to directly affect the body's state, use [method _integrate_forces], which allows you to directly access the physics state.
Please also keep in mind that physics bodies manage their own transform which overwrites the ones you set. So any direct or indirect transformation (including scaling of the node or its parent) will be visible in the editor only, and immediately reset at runtime.
If you need to override the default physics behavior or add a transformation at runtime, you can write a custom force integration. See [member custom_integrator].
</description>
<tutorials>
<link title="2D Physics Platformer Demo">https://godotengine.org/asset-library/asset/119</link>
<link title="Instancing Demo">https://godotengine.org/asset-library/asset/148</link>
</tutorials>
<methods>
<method name="_integrate_forces" qualifiers="virtual">
<return type="void" />
<param index="0" name="state" type="PhysicsDirectBodyState2D" />
<description>
Allows you to read and safely modify the simulation state for the object. Use this instead of [method Node._physics_process] if you need to directly change the body's [code]position[/code] or other physics properties. By default, it works in addition to the usual physics behavior, but [member custom_integrator] allows you to disable the default behavior and write custom force integration for a body.
</description>
</method>
<method name="add_constant_central_force">
<return type="void" />
<param index="0" name="force" type="Vector2" />
<description>
Adds a constant directional force without affecting rotation that keeps being applied over time until cleared with [code]constant_force = Vector2(0, 0)[/code].
This is equivalent to using [method add_constant_force] at the body's center of mass.
</description>
</method>
<method name="add_constant_force">
<return type="void" />
<param index="0" name="force" type="Vector2" />
<param index="1" name="position" type="Vector2" default="Vector2(0, 0)" />
<description>
Adds a constant positioned force to the body that keeps being applied over time until cleared with [code]constant_force = Vector2(0, 0)[/code].
[param position] is the offset from the body origin in global coordinates.
</description>
</method>
<method name="add_constant_torque">
<return type="void" />
<param index="0" name="torque" type="float" />
<description>
Adds a constant rotational force without affecting position that keeps being applied over time until cleared with [code]constant_torque = 0[/code].
</description>
</method>
<method name="apply_central_force">
<return type="void" />
<param index="0" name="force" type="Vector2" />
<description>
Applies a directional force without affecting rotation. A force is time dependent and meant to be applied every physics update.
This is equivalent to using [method apply_force] at the body's center of mass.
</description>
</method>
<method name="apply_central_impulse">
<return type="void" />
<param index="0" name="impulse" type="Vector2" default="Vector2(0, 0)" />
<description>
Applies a directional impulse without affecting rotation.
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 (use the "_force" functions otherwise).
This is equivalent to using [method apply_impulse] at the body's center of mass.
</description>
</method>
<method name="apply_force">
<return type="void" />
<param index="0" name="force" type="Vector2" />
<param index="1" name="position" type="Vector2" default="Vector2(0, 0)" />
<description>
Applies a positioned force to the body. A force is time dependent and meant to be applied every physics update.
[param position] is the offset from the body origin in global coordinates.
</description>
</method>
<method name="apply_impulse">
<return type="void" />
<param index="0" name="impulse" type="Vector2" />
<param index="1" name="position" type="Vector2" default="Vector2(0, 0)" />
<description>
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 (use the "_force" functions otherwise).
[param position] is the offset from the body origin in global coordinates.
</description>
</method>
<method name="apply_torque">
<return type="void" />
<param index="0" name="torque" type="float" />
<description>
Applies a rotational force without affecting position. A force is time dependent and meant to be applied every physics update.
[b]Note:[/b] [member inertia] is required for this to work. To have [member inertia], an active [CollisionShape2D] must be a child of the node, or you can manually set [member inertia].
</description>
</method>
<method name="apply_torque_impulse">
<return type="void" />
<param index="0" name="torque" type="float" />
<description>
Applies a rotational impulse to the body without affecting the position.
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 (use the "_force" functions otherwise).
[b]Note:[/b] [member inertia] is required for this to work. To have [member inertia], an active [CollisionShape2D] must be a child of the node, or you can manually set [member inertia].
</description>
</method>
<method name="get_colliding_bodies" qualifiers="const">
<return type="Node2D[]" />
<description>
Returns a list of the bodies colliding with this one. Requires [member contact_monitor] to be set to [code]true[/code] and [member max_contacts_reported] to be set high enough to detect all the collisions.
[b]Note:[/b] 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.
</description>
</method>
<method name="get_contact_count" qualifiers="const">
<return type="int" />
<description>
Returns the number of contacts this body has with other bodies. By default, this returns 0 unless bodies are configured to monitor contacts (see [member contact_monitor]).
[b]Note:[/b] To retrieve the colliding bodies, use [method get_colliding_bodies].
</description>
</method>
<method name="set_axis_velocity">
<return type="void" />
<param index="0" name="axis_velocity" type="Vector2" />
<description>
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.
</description>
</method>
</methods>
<members>
<member name="angular_damp" type="float" setter="set_angular_damp" getter="get_angular_damp" default="0.0">
Damps the body's rotation. By default, the body will use the [b]Default Angular Damp[/b] in [b]Project &gt; Project Settings &gt; Physics &gt; 2d[/b] or any value override set by an [Area2D] the body is in. Depending on [member angular_damp_mode], you can set [member angular_damp] to be added to or to replace the body's damping value.
See [member ProjectSettings.physics/2d/default_angular_damp] for more details about damping.
</member>
<member name="angular_damp_mode" type="int" setter="set_angular_damp_mode" getter="get_angular_damp_mode" enum="RigidBody2D.DampMode" default="0">
Defines how [member angular_damp] is applied. See [enum DampMode] for possible values.
</member>
<member name="angular_velocity" type="float" setter="set_angular_velocity" getter="get_angular_velocity" default="0.0">
The body's rotational velocity in [i]radians[/i] per second.
</member>
<member name="can_sleep" type="bool" setter="set_can_sleep" getter="is_able_to_sleep" default="true">
If [code]true[/code], the body can enter sleep mode when there is no movement. See [member sleeping].
</member>
<member name="center_of_mass" type="Vector2" setter="set_center_of_mass" getter="get_center_of_mass" default="Vector2(0, 0)">
The body's custom center of mass, relative to the body's origin position, when [member center_of_mass_mode] is set to [constant CENTER_OF_MASS_MODE_CUSTOM]. This is the balanced point of the body, where applied forces only cause linear acceleration. Applying forces outside of the center of mass causes angular acceleration.
When [member center_of_mass_mode] is set to [constant CENTER_OF_MASS_MODE_AUTO] (default value), the center of mass is automatically computed.
</member>
<member name="center_of_mass_mode" type="int" setter="set_center_of_mass_mode" getter="get_center_of_mass_mode" enum="RigidBody2D.CenterOfMassMode" default="0">
Defines the way the body's center of mass is set. See [enum CenterOfMassMode] for possible values.
</member>
<member name="constant_force" type="Vector2" setter="set_constant_force" getter="get_constant_force" default="Vector2(0, 0)">
The body's total constant positional forces applied during each physics update.
See [method add_constant_force] and [method add_constant_central_force].
</member>
<member name="constant_torque" type="float" setter="set_constant_torque" getter="get_constant_torque" default="0.0">
The body's total constant rotational forces applied during each physics update.
See [method add_constant_torque].
</member>
<member name="contact_monitor" type="bool" setter="set_contact_monitor" getter="is_contact_monitor_enabled" default="false">
If [code]true[/code], the RigidBody2D will emit signals when it collides with another RigidBody2D.
[b]Note:[/b] By default the maximum contacts reported is set to 0, meaning nothing will be recorded, see [member max_contacts_reported].
</member>
<member name="continuous_cd" type="int" setter="set_continuous_collision_detection_mode" getter="get_continuous_collision_detection_mode" enum="RigidBody2D.CCDMode" default="0">
Continuous collision detection mode.
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 [enum CCDMode] for details.
</member>
<member name="custom_integrator" type="bool" setter="set_use_custom_integrator" getter="is_using_custom_integrator" default="false">
If [code]true[/code], internal force integration is disabled for this body. Aside from collision response, the body will only move as determined by the [method _integrate_forces] function.
</member>
<member name="freeze" type="bool" setter="set_freeze_enabled" getter="is_freeze_enabled" default="false">
If [code]true[/code], the body is frozen. Gravity and forces are not applied anymore.
See [member freeze_mode] to set the body's behavior when frozen.
For a body that is always frozen, use [StaticBody2D] or [AnimatableBody2D] instead.
</member>
<member name="freeze_mode" type="int" setter="set_freeze_mode" getter="get_freeze_mode" enum="RigidBody2D.FreezeMode" default="0">
The body's freeze mode. Can be used to set the body's behavior when [member freeze] is enabled. See [enum FreezeMode] for possible values.
For a body that is always frozen, use [StaticBody2D] or [AnimatableBody2D] instead.
</member>
<member name="gravity_scale" type="float" setter="set_gravity_scale" getter="get_gravity_scale" default="1.0">
Multiplies the gravity applied to the body. The body's gravity is calculated from the [b]Default Gravity[/b] value in [b]Project &gt; Project Settings &gt; Physics &gt; 2d[/b] and/or any additional gravity vector applied by [Area2D]s.
</member>
<member name="inertia" type="float" setter="set_inertia" getter="get_inertia" default="0.0">
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 property allows you to set a custom value.
If set to [code]0[/code], inertia is automatically computed (default value).
</member>
<member name="linear_damp" type="float" setter="set_linear_damp" getter="get_linear_damp" default="0.0">
Damps the body's movement. By default, the body will use the [b]Default Linear Damp[/b] in [b]Project &gt; Project Settings &gt; Physics &gt; 2d[/b] or any value override set by an [Area2D] the body is in. Depending on [member linear_damp_mode], you can set [member linear_damp] to be added to or to replace the body's damping value.
See [member ProjectSettings.physics/2d/default_linear_damp] for more details about damping.
</member>
<member name="linear_damp_mode" type="int" setter="set_linear_damp_mode" getter="get_linear_damp_mode" enum="RigidBody2D.DampMode" default="0">
Defines how [member linear_damp] is applied. See [enum DampMode] for possible values.
</member>
<member name="linear_velocity" type="Vector2" setter="set_linear_velocity" getter="get_linear_velocity" default="Vector2(0, 0)">
The body's linear velocity in pixels per second. Can be used sporadically, but [b]don't set this every frame[/b], because physics may run in another thread and runs at a different granularity. Use [method _integrate_forces] as your process loop for precise control of the body state.
</member>
<member name="lock_rotation" type="bool" setter="set_lock_rotation_enabled" getter="is_lock_rotation_enabled" default="false">
If [code]true[/code], the body cannot rotate. Gravity and forces only apply linear movement.
</member>
<member name="mass" type="float" setter="set_mass" getter="get_mass" default="1.0">
The body's mass.
</member>
<member name="max_contacts_reported" type="int" setter="set_max_contacts_reported" getter="get_max_contacts_reported" default="0">
The maximum number of contacts that will be recorded. Requires a value greater than 0 and [member contact_monitor] to be set to [code]true[/code] to start to register contacts. Use [method get_contact_count] to retrieve the count or [method get_colliding_bodies] to retrieve bodies that have been collided with.
[b]Note:[/b] 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).
</member>
<member name="physics_material_override" type="PhysicsMaterial" setter="set_physics_material_override" getter="get_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.
</member>
<member name="sleeping" type="bool" setter="set_sleeping" getter="is_sleeping" default="false">
If [code]true[/code], 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 [method apply_impulse] or [method apply_force] methods.
</member>
</members>
<signals>
<signal name="body_entered">
<param index="0" name="body" type="Node" />
<description>
Emitted when a collision with another [PhysicsBody2D] or [TileMap] occurs. Requires [member contact_monitor] to be set to [code]true[/code] and [member max_contacts_reported] to be set high enough to detect all the collisions. [TileMap]s are detected if the [TileSet] has Collision [Shape2D]s.
[param body] the [Node], if it exists in the tree, of the other [PhysicsBody2D] or [TileMap].
</description>
</signal>
<signal name="body_exited">
<param index="0" name="body" type="Node" />
<description>
Emitted when the collision with another [PhysicsBody2D] or [TileMap] ends. Requires [member contact_monitor] to be set to [code]true[/code] and [member max_contacts_reported] to be set high enough to detect all the collisions. [TileMap]s are detected if the [TileSet] has Collision [Shape2D]s.
[param body] the [Node], if it exists in the tree, of the other [PhysicsBody2D] or [TileMap].
</description>
</signal>
<signal name="body_shape_entered">
<param index="0" name="body_rid" type="RID" />
<param index="1" name="body" type="Node" />
<param index="2" name="body_shape_index" type="int" />
<param index="3" name="local_shape_index" type="int" />
<description>
Emitted when one of this RigidBody2D's [Shape2D]s collides with another [PhysicsBody2D] or [TileMap]'s [Shape2D]s. Requires [member contact_monitor] to be set to [code]true[/code] and [member max_contacts_reported] to be set high enough to detect all the collisions. [TileMap]s are detected if the [TileSet] has Collision [Shape2D]s.
[param body_rid] the [RID] of the other [PhysicsBody2D] or [TileSet]'s [CollisionObject2D] used by the [PhysicsServer2D].
[param body] the [Node], if it exists in the tree, of the other [PhysicsBody2D] or [TileMap].
[param body_shape_index] the index of the [Shape2D] of the other [PhysicsBody2D] or [TileMap] used by the [PhysicsServer2D]. Get the [CollisionShape2D] node with [code]body.shape_owner_get_owner(body.shape_find_owner(body_shape_index))[/code].
[param local_shape_index] the index of the [Shape2D] of this RigidBody2D used by the [PhysicsServer2D]. Get the [CollisionShape2D] node with [code]self.shape_owner_get_owner(self.shape_find_owner(local_shape_index))[/code].
</description>
</signal>
<signal name="body_shape_exited">
<param index="0" name="body_rid" type="RID" />
<param index="1" name="body" type="Node" />
<param index="2" name="body_shape_index" type="int" />
<param index="3" name="local_shape_index" type="int" />
<description>
Emitted when the collision between one of this RigidBody2D's [Shape2D]s and another [PhysicsBody2D] or [TileMap]'s [Shape2D]s ends. Requires [member contact_monitor] to be set to [code]true[/code] and [member max_contacts_reported] to be set high enough to detect all the collisions. [TileMap]s are detected if the [TileSet] has Collision [Shape2D]s.
[param body_rid] the [RID] of the other [PhysicsBody2D] or [TileSet]'s [CollisionObject2D] used by the [PhysicsServer2D].
[param body] the [Node], if it exists in the tree, of the other [PhysicsBody2D] or [TileMap].
[param body_shape_index] the index of the [Shape2D] of the other [PhysicsBody2D] or [TileMap] used by the [PhysicsServer2D]. Get the [CollisionShape2D] node with [code]body.shape_owner_get_owner(body.shape_find_owner(body_shape_index))[/code].
[param local_shape_index] the index of the [Shape2D] of this RigidBody2D used by the [PhysicsServer2D]. Get the [CollisionShape2D] node with [code]self.shape_owner_get_owner(self.shape_find_owner(local_shape_index))[/code].
</description>
</signal>
<signal name="sleeping_state_changed">
<description>
Emitted when the physics engine changes the body's sleeping state.
[b]Note:[/b] Changing the value [member sleeping] will not trigger this signal. It is only emitted if the sleeping state is changed by the physics engine or [code]emit_signal("sleeping_state_changed")[/code] is used.
</description>
</signal>
</signals>
<constants>
<constant name="FREEZE_MODE_STATIC" value="0" enum="FreezeMode">
Static body freeze mode (default). The body is not affected by gravity and forces. It can be only moved by user code and doesn't collide with other bodies along its path.
</constant>
<constant name="FREEZE_MODE_KINEMATIC" value="1" enum="FreezeMode">
Kinematic body freeze mode. Similar to [constant FREEZE_MODE_STATIC], but collides with other bodies along its path when moved. Useful for a frozen body that needs to be animated.
</constant>
<constant name="CENTER_OF_MASS_MODE_AUTO" value="0" enum="CenterOfMassMode">
In this mode, the body's center of mass is calculated automatically based on its shapes.
</constant>
<constant name="CENTER_OF_MASS_MODE_CUSTOM" value="1" enum="CenterOfMassMode">
In this mode, the body's center of mass is set through [member center_of_mass]. Defaults to the body's origin position.
</constant>
<constant name="DAMP_MODE_COMBINE" value="0" enum="DampMode">
In this mode, the body's damping value is added to any value set in areas or the default value.
</constant>
<constant name="DAMP_MODE_REPLACE" value="1" enum="DampMode">
In this mode, the body's damping value replaces any value set in areas or the default value.
</constant>
<constant name="CCD_MODE_DISABLED" value="0" enum="CCDMode">
Continuous collision detection disabled. This is the fastest way to detect body collisions, but can miss small, fast-moving objects.
</constant>
<constant name="CCD_MODE_CAST_RAY" value="1" enum="CCDMode">
Continuous collision detection enabled using raycasting. This is faster than shapecasting but less precise.
</constant>
<constant name="CCD_MODE_CAST_SHAPE" value="2" enum="CCDMode">
Continuous collision detection enabled using shapecasting. This is the slowest CCD method and the most precise.
</constant>
</constants>
</class>