3D physics engine Reference

The 3D physics engine simulates realistic object physics, with gravity, forces, collisions, joints, etc. It's perfect for almost all 3D games.

Objects like floors or wall objects should usually be set to "Static" as type. Objects that should be moveable are usually "Dynamic" (default). "Kinematic" objects (typically, players or controlled characters) are only moved by their "linear velocity" and "angular velocity" - they can interact with other objects but only these other objects will move.

Forces (and impulses) are expressed in all conditions/expressions/actions of the 3D physics engine in Newtons (N). Typical values for a force are 10-200 N. One meter is 100 pixels by default in the game (check the world scale). Mass is expressed in kilograms (kg). Read more explanations about it.

Conditions

Collision
Check if two objects collide.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 👾 Object
Parameter 3: 🧩 Behavior

Technical note: parameter 4 are internal parameters handled by GDevelop.

Collision started
Check if two objects just started colliding during this frame.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 👾 Object
Parameter 3: 🧩 Behavior

Technical note: parameter 4 are internal parameters handled by GDevelop.

Collision stopped
Check if two objects just stopped colliding at this frame.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 👾 Object
Parameter 3: 🧩 Behavior

Technical note: parameter 4 are internal parameters handled by GDevelop.

Character is on given platform
Check if a 3D physics character is on a given platform.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (👾 Object): Platforms
Parameter 3: 🧩 Behavior

Technical note: parameter 4 are internal parameters handled by GDevelop.

3D physics engine

Simulate realistic 3D physics for this object including gravity, forces, collisions, etc.

Behavior actions

Apply angular impulse (rotational impulse)
Apply an angular impulse (also called a "rotational impulse") to the object. It instantly changes the rotation speed, to give an initial speed for instance.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Angular impulse around X (N·m·s)
Parameter 3 (🔢 Number): Angular impulse around Y (N·m·s)
Parameter 4 (🔢 Number): Angular impulse around Z (N·m·s) An impulse is like a rotation speed addition but depends on the mass.

Apply force (at a point)
Apply a force to the object over time. It "accelerates" an object and must be used every frame during a time period.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): X component (N)
Parameter 3 (🔢 Number): Y component (N)
Parameter 4 (🔢 Number): Z component (N) A force is like an acceleration but depends on the mass.
Parameter 5 (🔢 Number): Application point on X axis
Parameter 6 (🔢 Number): Application point on Y axis
Parameter 7 (🔢 Number): Application point on Z axis Use MassCenterX, MassCenterY and MassCenterZ expressions to avoid any rotation.

Apply force (at center)
Apply a force to the object over time. It "accelerates" an object and must be used every frame during a time period.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): X component (N)
Parameter 3 (🔢 Number): Y component (N)
Parameter 4 (🔢 Number): Z component (N) A force is like an acceleration but depends on the mass.

Apply force toward position
Apply a force to the object over time to move it toward a position. It "accelerates" an object and must be used every frame during a time period.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Length (N) A force is like an acceleration but depends on the mass.
Parameter 3 (🔢 Number): X position
Parameter 4 (🔢 Number): Y position
Parameter 5 (🔢 Number): Z position

Apply impulse (at a point)
Apply an impulse to the object. It instantly changes the speed, to give an initial speed for instance.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): X component (N·s or kg·m·s⁻¹)
Parameter 3 (🔢 Number): Y component (N·s or kg·m·s⁻¹)
Parameter 4 (🔢 Number): Z component (N·s or kg·m·s⁻¹) An impulse is like a speed addition but depends on the mass.
Parameter 5 (🔢 Number): Application point on X axis
Parameter 6 (🔢 Number): Application point on Y axis
Parameter 7 (🔢 Number): Application point on Z axis Use MassCenterX, MassCenterY and MassCenterZ expressions to avoid any rotation.

Apply impulse (at center)
Apply an impulse to the object. It instantly changes the speed, to give an initial speed for instance.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): X component (N·s or kg·m·s⁻¹)
Parameter 3 (🔢 Number): Y component (N·s or kg·m·s⁻¹)
Parameter 4 (🔢 Number): Z component (N·s or kg·m·s⁻¹) An impulse is like a speed addition but depends on the mass.

Apply impulse toward position
Apply an impulse to the object to move it toward a position. It instantly changes the speed, to give an initial speed for instance.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Length (N·s or kg·m·s⁻¹) An impulse is like a speed addition but depends on the mass.
Parameter 3 (🔢 Number): X position
Parameter 4 (🔢 Number): Y position
Parameter 5 (🔢 Number): Z position

Apply torque (rotational force)
Apply a torque (also called "rotational force") to the object. It "accelerates" an object rotation and must be used every frame during a time period.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Torque around X (N·m)
Parameter 3 (🔢 Number): Torque around Y (N·m)
Parameter 4 (🔢 Number): Torque around Z (N·m) A torque is like a rotation acceleration but depends on the mass.

Enable layer
Enable or disable a layer for an object. Two objects collide if any layer of the first object matches any mask of the second one and vice versa.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Layer (1 - 8)
Parameter 3 (❓ Yes or No): Enable

Enable mask
Enable or disable a mask for an object. Two objects collide if any layer of the first object matches any mask of the second one and vice versa.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Mask (1 - 8)
Parameter 3 (❓ Yes or No): Enable

Angular damping
Change the object angular damping. How much angular speed is lost across the time..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Angular velocity X
Change the object angular velocity around X.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Angular speed (in degrees per second)

Angular velocity Y
Change the object angular velocity around Y.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Angular speed (in degrees per second)

Angular velocity Z
Change the object angular velocity around Z.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Angular speed (in degrees per second)

Treat as bullet
Treat the object as a bullet. Better collision handling on high speeds at cost of some performance.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (❓ Yes or No): Treat as bullet

Density
Change the object density. The body's density and volume determine its mass..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Fixed rotation
Enable or disable an object fixed rotation. If enabled the object won't be able to rotate. This action has no effect on characters.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (❓ Yes or No): Fixed rotation

Friction
Change the object friction. How much energy is lost from the movement of one object over another. The combined friction from two bodies is calculated as 'sqrt(bodyA.friction * bodyB.friction)'..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Gravity scale
Change the object gravity scale. The gravity applied to an object is the world gravity multiplied by the object gravity scale..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Scale (1 by default)

World gravity on X axis
Change the world gravity on X axis While an object is needed, this will apply to all objects using the behavior..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Gravity (in Newton)

World gravity on Y axis
Change the world gravity on Y axis While an object is needed, this will apply to all objects using the behavior..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Gravity (in Newton)

World gravity on Z axis
Change the world gravity on Z axis While an object is needed, this will apply to all objects using the behavior..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Gravity (in Newton)

Linear damping
Change the object linear damping. How much movement speed is lost across the time..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Linear velocity X
Change the object linear velocity on X.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Linear velocity Y
Change the object linear velocity on Y.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Linear velocity Z
Change the object linear velocity on Z.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Restitution
Change the object restitution. Energy conservation on collision. The combined restitution from two bodies is calculated as 'max(bodyA.restitution, bodyB.restitution)'..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Shape offset X
Change the object shape offset on X..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Shape offset Y
Change the object shape offset on Y..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Shape offset Z
Change the object shape offset on Z..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Value

Shape scale
Modify an object shape scale. It affects custom shape dimensions, if custom dimensions are not set the body will be scaled automatically to the object size.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Scale (1 by default)

Behavior conditions

Angular damping
Compare the object angular damping. How much angular speed is lost across the time..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Angular velocity X
Compare the object angular velocity around X.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Angular speed (in degrees per second)

Angular velocity Y
Compare the object angular velocity around Y.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Angular speed (in degrees per second)

Angular velocity Z
Compare the object angular velocity around Z.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Angular speed (in degrees per second)

Density
Compare the object density. The body's density and volume determine its mass..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Friction
Compare the object friction. How much energy is lost from the movement of one object over another. The combined friction from two bodies is calculated as 'sqrt(bodyA.friction * bodyB.friction)'..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Gravity scale
Compare the object gravity scale. The gravity applied to an object is the world gravity multiplied by the object gravity scale..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Scale (1 by default)

World gravity on X axis
Compare the world gravity on X axis While an object is needed, this will apply to all objects using the behavior..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Gravity (in Newton)

World gravity on Y axis
Compare the world gravity on Y axis While an object is needed, this will apply to all objects using the behavior..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Gravity (in Newton)

World gravity on Z axis
Compare the world gravity on Z axis While an object is needed, this will apply to all objects using the behavior..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Gravity (in Newton)

Has fixed rotation
Check if an object has fixed rotation.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Is treated as a bullet
Check if the object is being treated as a bullet.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Is dynamic
Check if an object is dynamic.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Is kinematic
Check if an object is kinematic.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Is static
Check if an object is static.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Layer enabled
Check if an object has a specific layer enabled.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Layer (1 - 8)

Linear damping
Compare the object linear damping. How much movement speed is lost across the time..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Linear velocity
Compare the object linear velocity length.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed to compare to (in pixels per second)

Linear velocity X
Compare the object linear velocity on X.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Linear velocity Y
Compare the object linear velocity on Y.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Linear velocity Z
Compare the object linear velocity on Z.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Mask enabled
Check if an object has a specific mask enabled.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Mask (1 - 8)

Restitution
Compare the object restitution. Energy conservation on collision. The combined restitution from two bodies is calculated as 'max(bodyA.restitution, bodyB.restitution)'..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Shape offset X
Compare the object shape offset on X..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Shape offset Y
Compare the object shape offset on Y..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Shape offset Z
Compare the object shape offset on Z..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Value to compare

Behavior expressions

Expression	Description
`Object.Physics3D::AngularDamping()`	Return the object angular damping. How much angular speed is lost across the time..
`Object.Physics3D::AngularVelocityX()`	Return the object angular velocity around X.
`Object.Physics3D::AngularVelocityY()`	Return the object angular velocity around Y.
`Object.Physics3D::AngularVelocityZ()`	Return the object angular velocity around Z.
`Object.Physics3D::Density()`	Return the object density. The body's density and volume determine its mass..
`Object.Physics3D::Friction()`	Return the object friction. How much energy is lost from the movement of one object over another. The combined friction from two bodies is calculated as 'sqrt(bodyA.friction * bodyB.friction)'..
`Object.Physics3D::GravityScale()`	Return the object gravity scale. The gravity applied to an object is the world gravity multiplied by the object gravity scale..
`Object.Physics3D::GravityX()`	Return the world gravity on X axis While an object is needed, this will apply to all objects using the behavior..
`Object.Physics3D::GravityY()`	Return the world gravity on Y axis While an object is needed, this will apply to all objects using the behavior..
`Object.Physics3D::GravityZ()`	Return the world gravity on Z axis While an object is needed, this will apply to all objects using the behavior..
`Object.Physics3D::InertiaAroundX()`	Return the inertia around X axis of the object (in kilograms · meters²) when for its default rotation is (0°; 0°; 0°)
`Object.Physics3D::InertiaAroundY()`	Return the inertia around Y axis of the object (in kilograms · meters²) when for its default rotation is (0°; 0°; 0°)
`Object.Physics3D::InertiaAroundZ()`	Return the inertia around Z axis of the object (in kilograms · meters²) when for its default rotation is (0°; 0°; 0°)
`Object.Physics3D::LinearDamping()`	Return the object linear damping. How much movement speed is lost across the time..
`Object.Physics3D::LinearVelocityLength()`	Return the object linear velocity length.
`Object.Physics3D::LinearVelocityX()`	Return the object linear velocity on X.
`Object.Physics3D::LinearVelocityY()`	Return the object linear velocity on Y.
`Object.Physics3D::LinearVelocityZ()`	Return the object linear velocity on Z.
`Object.Physics3D::Mass()`	Return the mass of the object (in kilograms)
`Object.Physics3D::MassCenterX()`	Mass center X
`Object.Physics3D::MassCenterY()`	Mass center Y
`Object.Physics3D::MassCenterZ()`	Mass center Z
`Object.Physics3D::Restitution()`	Return the object restitution. Energy conservation on collision. The combined restitution from two bodies is calculated as 'max(bodyA.restitution, bodyB.restitution)'..
`Object.Physics3D::ShapeOffsetX()`	Return the object shape offset on X..
`Object.Physics3D::ShapeOffsetY()`	Return the object shape offset on Y..
`Object.Physics3D::ShapeOffsetZ()`	Return the object shape offset on Z..
`Object.Physics3D::WorldScale()`	Return the world scale.

3D physics car

Simulate a realistic car using the 3D physics engine. This is mostly useful for the car controlled by the player (it's usually too complex for other cars in a game).

This behavior is usually used with one or more "mapper" behavior to let the player move it.

Behavior actions

Engine inertia
Change the engine inertia (kg·m²). It slows down car acceleration.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Engine inertia (kg·m²)

Engine max speed
Change the engine max speed (RPM).

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Engine max speed (RPM)

Engine max torque
Change the engine max torque (N·m). It allows cars to climb steep slopes and push heavy obstacles.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Engine max torque (N·m)

Simulate accelerator stick control
Simulate an accelerator stick control.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Stick force (between -1 and 1)

Simulate move backward key press
Simulate a press of the move backward key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate move forward key press
Simulate a press of the move forward key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate hand brake key press
Simulate a press of the hand brake key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate move left key press
Simulate a press of the move left key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate move right key press
Simulate a press of the move right key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate steering stick control
Simulate a steering stick control.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Stick force (between -1 and 1)

Behavior conditions

Current gear
Compare the current gear (-1 = reverse, 0 = neutral, 1 = 1st gear).

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Current gear

Engine inertia
Compare the engine inertia (kg·m²). It slows down car acceleration.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Engine inertia (kg·m²)

Engine speed
Compare the current engine speed (RPM).

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Engine speed (RPM)

Engine max speed
Compare the engine max speed (RPM).

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Engine max speed (RPM)

Engine max torque
Compare the engine max torque (N·m). It allows cars to climb steep slopes and push heavy obstacles.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Engine max torque (N·m)

Is on floor
Check if any wheel is in contact with the ground.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Steer angle
Compare the current steer angle (in degree). The value is negative when cars turn left.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Steer angle (in degree)

Behavior expressions

Expression	Description
`Object.PhysicsCar3D::CurrentGear()`	Return the current gear (-1 = reverse, 0 = neutral, 1 = 1st gear).
`Object.PhysicsCar3D::EngineInertia()`	Return the engine inertia (kg·m²). It slows down car acceleration.
`Object.PhysicsCar3D::EngineSpeed()`	Return the current engine speed (RPM).
`Object.PhysicsCar3D::EngineSpeedMax()`	Return the engine max speed (RPM).
`Object.PhysicsCar3D::EngineTorqueMax()`	Return the engine max torque (N·m). It allows cars to climb steep slopes and push heavy obstacles.
`Object.PhysicsCar3D::SteerAngle()`	Return the current steer angle (in degree). The value is negative when cars turn left.

3D physics character

Allow an object to jump and run on platforms that have the 3D physics behavior(and which are generally set to "Static" as type, unless the platform is animated/moved in events).

This behavior is usually used with one or more "mapper" behavior to let the player move it.

Behavior actions

Abort jump
Abort the current jump and stop the object vertically. This action doesn't have any effect when the character is not jumping.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Maximum falling speed
Change the maximum falling speed of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Max speed (in pixels per second)
Parameter 4 (❓ Yes or No): If jumping, try to preserve the current speed in the air

Allow jumping again
When this action is executed, the object is able to jump again, even if it is in the air: this can be useful to allow a double jump for example. This is not a permanent effect: you must call again this action every time you want to allow the object to jump (apart if it's on the floor).

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Forbid jumping again in the air
This revokes the effect of "Allow jumping again". The object is made unable to jump while in mid air. This has no effect if the object is not in the air.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Current falling speed
Change Compare the current falling speed of the object. Its value is always positive..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed to compare to (in pixels per second)

Current forward speed
Change the current forward speed of the object. The object moves backward with negative values and forward with positive ones.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Current jump speed
Change Compare the current jump speed of the object. Its value is always positive..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed to compare to (in pixels per second)

Current sideways speed
Change the current sideways speed of the object. The object moves to the left with negative values and to the right with positive ones.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Forward acceleration
Change the forward acceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Acceleration (in pixels per second per second)

Forward angle
Change the angle used by the character to go forward.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Angle (in degrees)

Forward deceleration
Change the forward deceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Deceleration (in pixels per second per second)

Forward max speed
Change the forward max speed of the object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Gravity
Change the gravity applied on an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Gravity (in pixels per second per second)

Jump speed
Change the jump speed of an object. Its value is always positive.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Jump sustain time
Change the jump sustain time of an object. This is the time during which keeping the jump button held allow the initial jump speed to be maintained.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Duration (in seconds)

Should bind object and forward angle
Enable or disable keeping the object angle and forward angle the same.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (❓ Yes or No): Keep object angle and forward direction the same

Sideways acceleration
Change the sideways acceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Acceleration (in pixels per second per second)

Sideways deceleration
Change the sideways deceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Deceleration (in pixels per second per second)

Sideways max speed
Change the sideways max speed of the object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Simulate move backward key press
Simulate a press of the move backward key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate move forward key press
Simulate a press of the move forward key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate jump key press
Simulate a press of the jump key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate move left key press
Simulate a press of the move left key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate move right key press
Simulate a press of the move right key.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Simulate stick control
Simulate a stick control.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Stick angle (in degrees)
Parameter 3 (🔢 Number): Stick force (between 0 and 1)

Behavior conditions

Can jump
Check if the object can jump.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Current falling speed
Compare Compare the current falling speed of the object. Its value is always positive..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed to compare to (in pixels per second)

Current forward speed
Compare the current forward speed of the object. The object moves backward with negative values and forward with positive ones.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Current jump speed
Compare Compare the current jump speed of the object. Its value is always positive..

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed to compare to (in pixels per second)

Current sideways speed
Compare the current sideways speed of the object. The object moves to the left with negative values and to the right with positive ones.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Maximum falling speed
Compare the maximum falling speed of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Max speed (in pixels per second)

Forward acceleration
Compare the forward acceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Acceleration (in pixels per second per second)

Forward deceleration
Compare the forward deceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Deceleration (in pixels per second per second)

Forward max speed
Compare the forward max speed of the object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Gravity
Compare the gravity applied on an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Gravity (in pixels per second per second)

Is falling
Check if the object is falling.
Note that the object can be flagged as jumping and falling at the same time: at the end of a jump, the fall speed becomes higher than the jump speed.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Forward angle
Compare the angle used by the character to go forward.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2 (🔢 Number): Angle (in degrees)
Parameter 3 (🔢 Number): Tolerance (in degrees)

Is jumping
Check if the object is jumping.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Is moving
Check if the object is moving (whether it is on the floor or in the air).

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Is on floor
Check if the object is on a platform.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Jump speed
Compare the jump speed of an object. Its value is always positive.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Jump sustain time
Compare the jump sustain time of an object. This is the time during which keeping the jump button held allow the initial jump speed to be maintained.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Duration (in seconds)

Should bind object and forward angle
Check if the object angle and forward angle should be kept the same.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior

Sideways acceleration
Compare the sideways acceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Acceleration (in pixels per second per second)

Sideways deceleration
Compare the sideways deceleration of an object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Deceleration (in pixels per second per second)

Sideways max speed
Compare the sideways max speed of the object.

See parameters

Parameter 0: 👾 Object
Parameter 1: 🧩 Behavior
Parameter 2: 🟰 Relational operator
Parameter 3 (🔢 Number): Speed (in pixels per second)

Behavior expressions

Expression	Description
`Object.PhysicsCharacter3D::CurrentFallSpeed()`	Return Compare the current falling speed of the object. Its value is always positive..
`Object.PhysicsCharacter3D::CurrentForwardSpeed()`	Return the current forward speed of the object. The object moves backward with negative values and forward with positive ones.
`Object.PhysicsCharacter3D::CurrentJumpSpeed()`	Return Compare the current jump speed of the object. Its value is always positive..
`Object.PhysicsCharacter3D::CurrentSidewaysSpeed()`	Return the current sideways speed of the object. The object moves to the left with negative values and to the right with positive ones.
`Object.PhysicsCharacter3D::FallingSpeedMax()`	Return the maximum falling speed of an object.
`Object.PhysicsCharacter3D::ForwardAcceleration()`	Return the forward acceleration of an object.
`Object.PhysicsCharacter3D::ForwardAngle()`	Return the angle used by the character to go forward.
`Object.PhysicsCharacter3D::ForwardDeceleration()`	Return the forward deceleration of an object.
`Object.PhysicsCharacter3D::ForwardSpeedMax()`	Return the forward max speed of the object.
`Object.PhysicsCharacter3D::Gravity()`	Return the gravity applied on an object.
`Object.PhysicsCharacter3D::JumpSpeed()`	Return the jump speed of an object. Its value is always positive.
`Object.PhysicsCharacter3D::JumpSustainTime()`	Return the jump sustain time of an object. This is the time during which keeping the jump button held allow the initial jump speed to be maintained.
`Object.PhysicsCharacter3D::SidewaysAcceleration()`	Return the sideways acceleration of an object.
`Object.PhysicsCharacter3D::SidewaysDeceleration()`	Return the sideways deceleration of an object.
`Object.PhysicsCharacter3D::SidewaysSpeedMax()`	Return the sideways max speed of the object.

The 3D physics engine extension is always installed in all GDevelop projects: there is no need to add it from the Project Manager.

This page is an auto-generated reference page about the 3D physics engine feature of GDevelop, the open-source, cross-platform game engine designed for everyone. Learn more about all GDevelop features here.