This documentation is about using Pose, Area, and Constraint components. To use 2D physics in the Unity Editor using components like the Rigidbody 2D component, refer to 2D physics instead.
Pose
Property
Description
Pose Source
Sets how Unity finds the Physics Pose component this area attaches to. The options are:
Auto: Searches this GameObject and its parents for a Physics Pose component.
Custom: Uses the Physics Pose component from the GameObject you set in the Pose Target property.
Pose Target
Attaches this area to the Physics Pose component on this GameObject. Drag a GameObject with a Physics Pose component from the Hierarchy window to this property, or select the picker (⊙). This property is available only if you set Pose Source to Custom.
Refresh Pose
Searches this GameObject and its parents again for a Physics Pose component. This property is available only if you set Pose Source to Auto.
Geometry
Property
Description
Geometry Asset
Sets an asset that sets the values of the properties in this section. By default, this property is empty, and Unity stores the values inside the component. To set a geometry asset instead, drag a Physics Capsule Geometry asset from the Project window to this property, or select the picker (⊙).
Make Asset
Converts the capsule geometry stored in the component into a Physics Capsule Geometry asset. This property is available only if you don't set a Geometry Asset.
Make Local
Removes the Geometry Asset and stores the capsule geometry inside the component. This property is available only if you set a Geometry Asset.
Center 1
Sets the local position of the center of one end of the capsule, relative to this component's position. The options are:
X: Sets the position along the x-axis.
Y: Sets the position along the y-axis.
The default is (0, 0.5).
Center 2
Sets the local position of the center of the other end of the capsule, relative to this component's position. The options are:
X: Sets the position along the x-axis.
Y: Sets the position along the y-axis.
The default is (0, -0.5).
Radius
Sets the radius of the two semi-circles at each end of the capsule. The value can't be negative. The default is 0.5.
Transformation
Property
Description
Position
Offsets the position of the area, relative to the Position property of the GameObject's Transform component.
Rotation
Offsets the rotation of the area in degrees, relative to the Rotation property of the GameObject's Transform component.
Scale
Offsets the scale of the area, relative to the Scale property of the GameObject's Transform component.
Scale Radius
Adjusts the radius of the object using both the Scale property in this section and the Scale property of the GameObject's Transform component.
Definition
The properties in this section set the properties of the shape.
Property
Description
Definition Asset
Sets an asset that sets the values of the properties in this section. By default, this property is empty, and Unity stores the values inside the component. To set a definition asset, drag a Physics Area Definition asset from the Project window to this property, or select the picker (⊙).
Definition Overrides
The properties in this section override the properties from the Definition Asset, or the local values if no Definition Asset is assigned.
Property
Description
Contact Asset
Sets a Physics Contact Filter asset that overrides the Contact Filter properties.
Material Asset
Sets a Physics Surface Material asset that overrides the Surface Material properties.
Assigns the shape to a group, and overrides the Categories and Contacts properties. Use the following values:
0
: Assigns no group. The shape uses the Categories and Contacts properties to determine collisions.
Positive value: The shape always collides with other shapes that have the same Group Index.
Negative value: The shape doesn't collide with other shapes that have the same Group Index.
Surface Material
The properties in the Surface Material section determine how the shape interacts with other shapes.
Property
Description
Friction
Sets the coefficient of friction for this collider. A value of 0 means no friction, like ice. A value of 1 means very high friction, like rubber. The default is 0.6.
Bounciness
Sets how bouncy the surface is, and how much other colliders bounce off it. A value of 0 means the surface isn't at all bouncy, like soft clay. A value of 1 means the surface is very bouncy, like rubber. The default is 0.
Friction Mixing
Determines the method Unity uses to mix the friction of two objects when they make contact. The options are:
Average: Uses the average of the two values.
Mean: Uses the geometric mean of the two values. The geometric mean multiplies the two values then returns the square root.
Multiply: Multiplies the two values together.
Minimum: Uses the smaller value.
Maximum: Uses the larger value.
Bounciness Mixing
Determines the method Unity uses to mix the bounciness of two objects when they make contact. The options are:
Average: Uses the average of the two values.
Mean: Uses the geometric mean of the two values. The geometric mean multiplies the two values then returns the square root.
Multiply: Multiplies the two values together.
Minimum: Uses the smaller value.
Maximum: Uses the larger value.
Friction Priority
Determines which shape contributes its Friction Mixing mode when two shapes come into contact. Unity uses the Friction Mixing mode from the shape with the highest Friction Priority value. If the two shapes have the same Friction Priority value, Unity uses the highest
SurfaceMaterial.MixingMode
enumeration value from the two shapes.
Bounciness Priority
Determines which shape contributes its Bounciness Mixing mode when two shapes come into contact. Unity uses the Bounciness Mixing mode from the shape with the highest Bounciness Priority value. If the two shapes have the same Bounciness Priority value, Unity uses the highest
SurfaceMaterial.MixingMode
enumeration value from the two shapes.
Rolling Resistance
Sets how resistant the shape is to rolling. The range of values is 0 to 1, where 0 means no rolling resistance and 1 means full rolling resistance.
Tangent Speed
Sets the speed the surface moves other objects that come into contact with it, in meters per second. For example, if you set Tangent Speed to 5, the surface acts like a conveyor belt that moves objects along the surface at 5 meters per second. You can use a positive or negative value to set the direction of movement.
Custom Color
Overrides the color Unity uses to draw the debug visualization of the shape. The alpha value is ignored. The default is
, which is black with an alpha of 0, and means Unity uses different colors to represent the current state of the shape. For more information, refer to Visualize and edit 2D Physics Core scenes.
Other properties
Property
Description
Density
Sets the density in kg/m^2. The default is 1. Use this property to create a hollow shape for example.
Is Trigger
Enables the shape going through other shapes without generating a collision response. Instead, the shape generates a trigger event when another shape overlaps. For more information, refer to Introduction to collision in 2D Physics Core.
Trigger Events
Produces a trigger event when the shape starts and ends overlapping another shape that has its Is Trigger property enabled. To fetch events, refer to
Produces a contact event when the shape starts and ends contact with another shape. This property has no effect if the shape is attached to a body set to Static. To fetch events, refer to
Produces a hit event when the shape collides with another shape. This property has no effect if the shape is attached to a body set to Static. To fetch events, refer to
method of the dynamic body before Unity calculates the collision response, so you can run your own code.
Start Static Contacts
Produces a contact event if the shape is attached to a body set to Static, and the shape makes contact with another shape. Enabling this property can reduce performance if you have many static shapes.
Start Mass Update
Updates the mass of the body when the shape is created. Disabling this property can improve performance if you add multiple shapes to the same body, but you must call
API instead of a Physics Area component. This property is available only if you set Callback Source to Area or Events.
Event settings
The properties in this section set the specific method this area calls or the parameter it sets when contact begins or ends. This section is available only if you set Callback Source to Events, and controls the behavior of one of the following methods of the component:
On Contact Begin (ContactBeginEvent)
and
On Contact End (ContactEndEvent)
, if Is Trigger is disabled.
On Trigger Begin (TriggerBeginEvent)
and
On Trigger End (TriggerEndEvent)
, If Is Trigger is enabled.
Property
Description
Activation
Sets when the object activates the callback method or parameter. The options are:
Off: Doesn't activate the callback method or parameter.
Editor and Runtime: Activates the callback method or parameter in the Unity Editor and at runtime.
Runtime Only: Activates the callback method or parameter only at runtime.
Object
Sets the object with the parameter to update or method to call. Drag any object from the Hierarchy or Project windows to this property, or select the picker (⊙).
Functions
Sets the parameter to update or the method to call. Select a parameter or method from the Object, its components, or its script methods. You can set the parameter value to update to, or the method parameters to use.
Add (+)
Adds a new callback method to the list.
Remove (-)
Removes the selected callback method from the list.
User Data
Use the properties in this section to add your own data to the component, and read it using the
This section displays information about the area. You can't directly edit the properties in this section.
Handle
Property
Description
Valid
The state of the object. True means the object is in the simulation.
World
The index number of the world the object belongs to. The default is 0, which is the default world.
Index
The index number of the object in the world.
Generation
The number of times Unity has used the same Index for different objects.
Callbacks
This section is visible only if you set Callback Source to a value other than Off.
Property
Description
Contact Begin
How many times a contact-begin callback was dispatched to a valid receiver this session. This property is visible only if the area's active definition isn't a trigger.
Contact End
How many times a contact-end callback was dispatched to a valid receiver this session. This property is visible only if the area's active definition isn't a trigger.
Trigger Begin
How many times a trigger-begin callback was dispatched to a valid receiver this session. This property is visible only if the area's active definition is a trigger.
Trigger End
How many times a trigger-end callback was dispatched to a valid receiver this session. This property is visible only if the area's active definition is a trigger.
Other properties
Property
Description
Shape Count
The number of different shapes attached to this area.