Unigine::JointWheel Class
Header: | #include <UniginePhysics.h> |
Inherits from: | Joint |
This class is used to create ray-cast wheels. Both a frame and a wheel are rigid bodies. There is no need to assign a shape to the wheel: ray casting is used to detect collision of the wheel with a surface.
Example#
The following code illustrates connection of two rigid bodies (frame and wheel) using a wheel joint.
include <UniginePhysics.h>
/* .. */
JointWheelPtr joint = JointWheel::create(frame, wheel);
// setting joint anchor coordinates
joint->setWorldAnchor(wheel->getObject()->getWorldTransform() * Vec3(0.0f));
// setting joint axes coordinates
joint->setWorldAxis0(vec3(0.0f,0.0f,1.0f));
joint->setWorldAxis1(vec3(0.0f,1.0f,0.0f));
// setting linear damping and spring rigidity
joint->setLinearDamping(200.0f);
joint->setLinearSpring(100.0f);
// setting lower and upper suspension ride limits [-1.0; 0.0]
joint->setLinearLimitFrom(-1.0f);
joint->setLinearLimitTo(0.0f);
// setting target suspension height
joint->setLinearDistance(0.5f);
// setting maximum angular velocity and torque
joint->setAngularVelocity(-20.0f);
joint->setAngularTorque(10.0f);
// setting wheel parameters
joint->setWheelRadius(0.5f);
joint->setWheelMass(4.0f);
joint->setWheelThreshold(0.1f);
// setting tyre friction parameters
joint->setTangentFriction(4.0f);
joint->setBinormalFriction(5.0f);
// setting number of iterations
joint->setNumIterations(8);
See Also#
- Creating a Car with Wheel Joints usage example.
- UnigineScript API sample <UnigineSDK>/data/samples/joints/wheel_00
- UnigineScript API sample <UnigineSDK>/data/samples/physics/car_01
JointWheel Class
Members
float getCurrentSlipRatio() const#
Returns the current ratio of wheel spin to ground speed.
Return value
Current current slip ratio, in percent. 0 means that the velocities are equal. If the throttle is pressed, the value will be positive. If the brake is pressed, the value will be negative.float getCurrentSlipAngle() const#
Returns the current angle between the wheel direction and the frame direction.
Return value
Current current slip angle in degrees.void setWheelThreshold ( float threshold ) #
Sets a new threshold difference between the wheel and ground velocities. When it is too small, the longitudinal force is scaled down to prevent unnatural vibrations.
Arguments
- float threshold - The difference threshold. If a negative value is provided, 0 will be used instead.
float getWheelThreshold() const#
Returns the current threshold difference between the wheel and ground velocities. When it is too small, the longitudinal force is scaled down to prevent unnatural vibrations.
Return value
Current difference threshold. If a negative value is provided, 0 will be used instead.void setWheelRadius ( float radius ) #
Sets a new radius of the attached wheel.
Arguments
- float radius - The radius of the wheel, in units. If a negative value is provided, 0 will be used instead.
float getWheelRadius() const#
Returns the current radius of the attached wheel.
Return value
Current radius of the wheel, in units. If a negative value is provided, 0 will be used instead.void setWheelMass ( float mass ) #
Sets a new mass of the attached wheel.
If g (Earth's gravity) equals to 9.8 m/s
2, and 1 unit equals to 1 m, the mass is measured in kilograms.
Arguments
- float mass - The mass of the wheel. If a negative value is provided, 0 will be used instead.
float getWheelMass() const#
Returns the current mass of the attached wheel.
If g (Earth's gravity) equals to 9.8 m/s
2, and 1 unit equals to 1 m, the mass is measured in kilograms.
Return value
Current mass of the wheel. If a negative value is provided, 0 will be used instead.void setTangentFriction ( float friction ) #
Sets a new longitudinal (forward) friction of the tire.
Arguments
- float friction - The longitudinal friction. If a negative value is provided, 0 will be used instead.
float getTangentFriction() const#
Returns the current longitudinal (forward) friction of the tire.
Return value
Current longitudinal friction. If a negative value is provided, 0 will be used instead.void setTangentAngle ( float angle ) #
Sets a new coefficient specifying how fast the optimal longitudinal force can be achieved. The larger this value, the more is the impulse produced by the tire.
Arguments
- float angle - The coefficient characterizing the tire longitudinal impulse. If a negative value is provided, 0 will be used instead.
float getTangentAngle() const#
Returns the current coefficient specifying how fast the optimal longitudinal force can be achieved. The larger this value, the more is the impulse produced by the tire.
Return value
Current coefficient characterizing the tire longitudinal impulse. If a negative value is provided, 0 will be used instead.void setBinormalFriction ( float friction ) #
Sets a new lateral (sideways) friction of the tire.
Arguments
- float friction - The lateral friction. If a negative value is provided, 0 will be used instead.
float getBinormalFriction() const#
Returns the current lateral (sideways) friction of the tire.
Return value
Current lateral friction. If a negative value is provided, 0 will be used instead.void setBinormalAngle ( float angle ) #
Sets a new coefficient specifying how fast the optimal lateral force can be achieved. The larger this value, the more is the impulse produced by the tire.
Arguments
- float angle - The coefficient characterizing the tire lateral impulse. If a negative value is provided, 0 will be used instead.
float getBinormalAngle() const#
Returns the current coefficient specifying how fast the optimal lateral force can be achieved. The larger this value, the more is the impulse produced by the tire.
Return value
Current coefficient characterizing the tire lateral impulse. If a negative value is provided, 0 will be used instead.void setCurrentAngularVelocity ( float velocity ) #
Sets a new rotation velocity of the attached wheels.
Arguments
- float velocity - The angular velocity in radians per second. Setting the value to 0 allows stopping the car when necessary.
float getCurrentAngularVelocity() const#
Returns the current rotation velocity of the attached wheels.
Return value
Current angular velocity in radians per second. Setting the value to 0 allows stopping the car when necessary.void setAngularVelocity ( float velocity ) #
Sets a new target velocity of wheel rotation.
Arguments
- float velocity - The target velocity, in radians per second.
float getAngularVelocity() const#
Returns the current target velocity of wheel rotation.
Return value
Current target velocity, in radians per second.void setAngularTorque ( float torque ) #
Sets a new maximum torque of the attached angular motor. 0 means that the motor is not attached.
Arguments
- float torque - The maximum torque. If a negative value is provided, 0 will be used instead. 0 detaches the motor.
float getAngularTorque() const#
Returns the current maximum torque of the attached angular motor. 0 means that the motor is not attached.
Return value
Current maximum torque. If a negative value is provided, 0 will be used instead. 0 detaches the motor.void setAngularDamping ( float damping ) #
Sets a new angular damping of the joint (wheel rotation damping).
Arguments
- float damping - The angular damping. If a negative value is provided, 0 will be used instead.
float getAngularDamping() const#
Returns the current angular damping of the joint (wheel rotation damping).
Return value
Current angular damping. If a negative value is provided, 0 will be used instead.void setCurrentLinearDistance ( float distance ) #
Sets a new The current suspension compression (i.e. the length of the suspension).
Arguments
- float distance - The suspension length, in units.
float getCurrentLinearDistance() const#
Returns the current The current suspension compression (i.e. the length of the suspension).
Return value
Current suspension length, in units.void setLinearSpring ( float spring ) #
Sets a new rigidity coefficient of the suspension. 0 means that the suspension is not attached.
Arguments
- float spring - The rigidity coefficient. If a negative value is provided, 0 will be used instead. 0 detaches the suspension.
float getLinearSpring() const#
Returns the current rigidity coefficient of the suspension. 0 means that the suspension is not attached.
Return value
Current rigidity coefficient. If a negative value is provided, 0 will be used instead. 0 detaches the suspension.void setLinearLimitTo ( float to ) #
Sets a new high limit of the suspension ride. This limit specifies how far a connected body can move along the joint axis.
Arguments
- float to - The high limit in units.
float getLinearLimitTo() const#
Returns the current high limit of the suspension ride. This limit specifies how far a connected body can move along the joint axis.
Return value
Current high limit in units.void setLinearLimitFrom ( float from ) #
Sets a new low limit of the suspension ride. This limit specifies how far a connected body can move along the joint axis.
Arguments
- float from - The low limit in units.
float getLinearLimitFrom() const#
Returns the current low limit of the suspension ride. This limit specifies how far a connected body can move along the joint axis.
Return value
Current low limit in units.void setLinearDistance ( float distance ) #
Sets a new target height of the suspension.
Arguments
- float distance - The height, in units.
float getLinearDistance() const#
Returns the current target height of the suspension.
Return value
Current height, in units.void setLinearDamping ( float damping ) #
Sets a new linear damping of the suspension.
Arguments
- float damping - The linear damping. If a negative value is provided, 0 will be used instead.
float getLinearDamping() const#
Returns the current linear damping of the suspension.
Return value
Current linear damping. If a negative value is provided, 0 will be used instead.void setPhysicsIntersectionMask ( int mask ) #
Sets a new physics intersection mask for the joint.integer, each bit of which is a mask.
Arguments
- int mask - The
int getPhysicsIntersectionMask() const#
Returns the current physics intersection mask for the joint.integer, each bit of which is a mask.
Return value
Currentvoid setWorldAxis0 ( const Math::vec3& axis0 ) #
Sets a new suspension axis in the world coordinates.
Arguments
- const Math::vec3& axis0 - The suspension axis in the world coordinates.
Math::vec3 getWorldAxis0() const#
Returns the current suspension axis in the world coordinates.
Return value
Current suspension axis in the world coordinates.void setWorldAxis1 ( const Math::vec3& axis1 ) #
Sets a new wheel spindle axis in the world coordinates.
Arguments
- const Math::vec3& axis1 - The wheel spindle axis in the world coordinates.
Math::vec3 getWorldAxis1() const#
Returns the current wheel spindle axis in the world coordinates.
Return value
Current wheel spindle axis in the world coordinates.void setAxis00 ( const Math::vec3& axis00 ) #
Sets a new coordinates of suspension axis, along which a wheel moves vertically. This is a shock absorber.
Arguments
- const Math::vec3& axis00 - The suspension axis, in the world coordinates.
Math::vec3 getAxis00() const#
Returns the current coordinates of suspension axis, along which a wheel moves vertically. This is a shock absorber.
Return value
Current suspension axis, in the world coordinates.void setAxis10 ( const Math::vec3& axis10 ) #
Sets a new wheel spindle axis in coordinates of the frame (body 0): an axis around which a wheel rotates when moving forward (or backward).
Arguments
- const Math::vec3& axis10 - The wheel spindle axis in coordinates of the frame (body 0).
Math::vec3 getAxis10() const#
Returns the current wheel spindle axis in coordinates of the frame (body 0): an axis around which a wheel rotates when moving forward (or backward).
Return value
Current wheel spindle axis in coordinates of the frame (body 0).void setAxis11 ( const Math::vec3& axis11 ) #
Sets a new wheel spindle axis in coordinates of the wheel (body 1): an axis around which a wheel rotates when steering.
Arguments
- const Math::vec3& axis11 - The wheel spindle axis in coordinates of the wheel (body 1).
Math::vec3 getAxis11() const#
Returns the current wheel spindle axis in coordinates of the wheel (body 1): an axis around which a wheel rotates when steering.
Return value
Current wheel spindle axis in coordinates of the wheel (body 1).static JointWheelPtr create ( ) #
Constructor. Creates a wheel joint with an anchor at the origin of the world coordinates.static JointWheelPtr create ( const Ptr<Body> & body0, const Ptr<Body> & body1 ) #
Constructor. Creates a wheel joint connecting two given bodies. An anchor is placed between centers of mass of the bodies.Arguments
- const Ptr<Body> & body0 - Frame to be connected with the joint.
- const Ptr<Body> & body1 - Wheel to be connected with the joint.
static JointWheelPtr create ( const Ptr<Body> & body0, const Ptr<Body> & body1, const Math::Vec3 & anchor, const Math::vec3 & axis0, const Math::vec3 & axis1 ) #
Constructor. Creates a wheel joint connecting two given bodies with specified suspension and spindle axis coordinates and an anchor placed at specified coordinates.Arguments
- const Ptr<Body> & body0 - Frame to be connected with the joint.
- const Ptr<Body> & body1 - Wheel to be connected with the joint.
- const Math::Vec3 & anchor - Anchor coordinates.
- const Math::vec3 & axis0 - Suspension axis coordinates.
- const Math::vec3 & axis1 - Wheel spindle axis coordinates.
Math::vec3 getContactNormal ( ) const#
Returns a normal of a point of contact with the ground, in world coordinates.Return value
Normal.Ptr<Object> getContactObject ( ) const#
Returns an object representing the ground.Return value
Ground object.Math::Vec3 getContactPoint ( ) const#
Returns a point of contact with the ground, in world coordinates.Return value
Point coordinates.Ptr<Shape> getContactShape ( ) const#
Returns a shape of the object representing the ground.Return value
Shape of the ground object.int getContactSurface ( ) const#
Returns a surface of a ground object, which is in contact.Return value
Surface number.void setCanBeUnderTerrain ( bool val ) #
Sets a value indicating if the Wheel Joint should be used under the surface of the terrain (drive in an underground parking or tunnel). This flag ensures proper behavior of the joint underground , otherwise the Wheel Joint will tend to pop up on the terrain surface above.Arguments
- bool val - true if the Wheel Joint is to be used under the surface of the terrain; otherwise, false.
Last update:
2024-08-16
Help improve this article
Was this article helpful?
(or select a word/phrase and press Ctrl+Enter)