43 lines
1.5 KiB
GDScript
43 lines
1.5 KiB
GDScript
class_name Wheel
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extends RayCast3D
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@export var wheel_radius: float = 0.316
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@export var flipped: bool = false
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@export_group("Suspension")
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@export var suspension_rest_length: float = 0.1
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@export var suspension_stiffness: float = 30_000
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@export var suspension_damping: float = 2000
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func _ready() -> void:
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target_position *= suspension_rest_length + wheel_radius
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$"RX-Wheel".rotate_y(PI if flipped else 0.0)
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func apply_forces(car: Car) -> void:
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force_raycast_update()
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var force: Vector3 = get_suspension_force(car)
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car.apply_force(force, car.to_local(get_collision_point()))
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func get_suspension_force(car: Car) -> Vector3:
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var up: Vector3 = global_basis.y
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if not is_colliding():
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$"RX-Wheel".position = -up * suspension_rest_length
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return Vector3.ZERO
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var collision_point: Vector3 = to_local(get_collision_point())
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var wheel_center: Vector3 = collision_point + (up * wheel_radius)
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$"RX-Wheel".position = wheel_center
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var suspension_length: float = -up.dot(wheel_center)
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var suspension_displacement: float = suspension_rest_length - suspension_length
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#https://en.wikipedia.org/wiki/Hookes_law
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var hookes_force_scalar: float = suspension_stiffness * suspension_displacement
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var wheel_velocity: Vector3 = car.get_velocity_at_point(car.to_local(to_global(wheel_center)))
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var wheel_up_velocity: float = up.dot(wheel_velocity)
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var damping_force_scalar: float = suspension_damping * wheel_up_velocity
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var y_force_scalar: float = hookes_force_scalar - damping_force_scalar
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var force: Vector3 = Vector3.UP * y_force_scalar
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return force
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