Unigine.JointWheel Class
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.
Source code (C#)
JointWheel joint = new JointWheel(frame, wheel);
// setting joint anchor coordinates
joint.WorldAnchor = wheel.Object.WorldTransform * new dvec3(0.0f));
// setting joint axes coordinates
joint.WorldAxis0 = new vec3(0.0f,0.0f,1.0f);
joint.WorldAxis1 = new vec3(0.0f,1.0f,0.0f);
// setting linear damping and spring rigidity
joint.LinearDamping = 200.0f;
joint.LinearSpring = 100.0f;
// setting lower and upper suspension ride limits [-1.0; 0.0]
joint.LinearLimitFrom = -1.0f;
joint.LinearLimitTo = 0.0f;
// setting target suspension height
joint.LinearDistance = 0.5f;
// setting maximum angular velocity and torque
joint.AngularVelocity = -20.0f;
joint.AngularTorque = 10.0f;
// setting wheel parameters
joint.WheelRadius = 0.5f;
joint.WheelMass = 4.0f;
joint.WheelThreshold = 0.1f;
// setting tyre friction parameters
joint.TangentFriction = 4.0f;
joint.BinormalFriction = 5.0f;
// setting number of iterations
joint.NumIterations = 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
Properties
float CurrentSlipRatio#
The current ratio of wheel spin to ground speed.
float CurrentSlipAngle#
The current angle between the wheel direction and the frame direction.
float WheelThreshold#
The threshold difference between the wheel and ground velocities. when it is too small, the longitudinal force will be scaled down to prevent unnatural vibrations.
float WheelRadius#
The radius of the attached wheel.
float WheelMass#
The mass of the attached wheel.
Notice
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.
float TangentFriction#
The longitudinal (forward) friction of the tire.
float TangentAngle#
The coefficient specifying how fast the optimal longitudinal force can be achieved. the larger this value, the more is the impulse produced by the tire.
float BinormalFriction#
The lateral (sideways) friction of the tire.
float BinormalAngle#
The coefficient specifying how fast the optimal lateral force can be achieved. the larger this value, the more is the impulse produced by the tire.
float CurrentAngularVelocity#
The current rotation velocity of the attached wheels.
float AngularVelocity#
The target velocity of wheel rotation.
float AngularTorque#
The maximum torque of the attached angular motor.
float AngularDamping#
The angular damping of the joint (wheel rotation damping).
float CurrentLinearDistance#
The current suspension compression (i.e. the length of the suspension).
float LinearSpring#
The rigidity coefficient of the suspension.
float LinearLimitTo#
The high limit of the suspension ride.
float LinearLimitFrom#
The low limit of the suspension ride.
float LinearDistance#
The target height of the suspension.
float LinearDamping#
The linear damping of the suspension.
int PhysicsIntersectionMask#
The A physics intersection mask of the joint.
vec3 WorldAxis1#
The wheel spindle axis in the world coordinates.
vec3 WorldAxis0#
The suspension axis in the world coordinates.
vec3 Axis11#
The wheel spindle in coordinates of the wheel (body 1).
vec3 Axis10#
The wheel spindle axis in coordinates of the frame (body 0).
vec3 Axis00#
The Suspension axis coordinates.
Members
JointWheel ( ) #
Constructor. Creates a wheel joint with an anchor at the origin of the world coordinates.JointWheel ( Body body0, Body body1 ) #
Constructor. Creates a wheel joint connecting two given bodies. An anchor is placed between centers of mass of the bodies.Arguments
- Body body0 - Frame to be connected with the joint.
- Body body1 - Wheel to be connected with the joint.
JointWheel ( Body body0, Body body1, vec3 anchor, vec3 axis0, 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
- Body body0 - Frame to be connected with the joint.
- Body body1 - Wheel to be connected with the joint.
- vec3 anchor - Anchor coordinates.
- vec3 axis0 - Suspension axis coordinates.
- vec3 axis1 - Wheel spindle axis coordinates.
vec3 GetContactNormal ( ) #
Returns a normal of a point of contact with the ground, in world coordinates.Return value
Normal.Object GetContactObject ( ) #
Returns an object representing the ground.Return value
Ground object.vec3 GetContactPoint ( ) #
Returns a point of contact with the ground, in world coordinates.Return value
Point coordinates.Shape GetContactShape ( ) #
Returns a shape of the object representing the ground.Return value
Shape of the ground object.int GetContactSurface ( ) #
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:
2023-12-19
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