thewheelbarrow/3d-car-game
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added engine force, air resistance, and rolling resistance

Browse Source 
also added debug draw 3d addon
This commit is contained in:
Wheelbarrow
2025-07-26 10:16:43 -04:00
parent a28e7d6d13
commit 15547fce8d
40 changed files with 566 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
wheel.gd
View File

@@ -3,40 +3,98 @@ extends RayCast3D
@export var wheel_radius: float = 0.316
@export var flipped: bool = false
@export var on_drivetrain: bool = false
@export var rolling_resistance: float = 2
@export_group("Suspension")
@export var suspension_rest_length: float = 0.1
@export var suspension_stiffness: float = 30_000
@export var suspension_damping: float = 2000
var car: Car
var _last_velocity: Vector3
func _ready() -> void:
target_position *= suspension_rest_length + wheel_radius
$"RX-Wheel".rotate_y(PI if flipped else 0.0)
func apply_forces(car: Car) -> void:
func set_new_car(new_car: Car) -> void:
car = new_car
# Little bit freaky but we put up with it
_last_velocity = car.get_velocity_at_point(get_collision_point())
func _physics_process(_delta: float) -> void:
force_raycast_update()
var force: Vector3 = get_suspension_force(car)
car.apply_force(force, car.to_local(get_collision_point()))
apply_suspension_force()
apply_rolling_resistance()
apply_engine_force()
_last_velocity = car.get_velocity_at_point(get_collision_point())
func get_suspension_force(car: Car) -> Vector3:
func apply_suspension_force() -> void:
var up: Vector3 = global_basis.y
if not is_colliding():
$"RX-Wheel".position = -up * suspension_rest_length
return Vector3.ZERO
return
var collision_point: Vector3 = to_local(get_collision_point())
var wheel_center: Vector3 = collision_point + (up * wheel_radius)
var wheel_center: Vector3 = get_wheel_center()
$"RX-Wheel".position = wheel_center
var suspension_length: float = -up.dot(wheel_center)
var suspension_displacement: float = suspension_rest_length - suspension_length
#https://en.wikipedia.org/wiki/Hookes_law
var hookes_force_scalar: float = suspension_stiffness * suspension_displacement
var wheel_velocity: Vector3 = car.get_velocity_at_point(car.to_local(to_global(wheel_center)))
var wheel_velocity: Vector3 = car.get_velocity_at_point(to_global(wheel_center))
var wheel_up_velocity: float = up.dot(wheel_velocity)
var damping_force_scalar: float = suspension_damping * wheel_up_velocity
var y_force_scalar: float = hookes_force_scalar - damping_force_scalar
var force: Vector3 = Vector3.UP * y_force_scalar
var force: Vector3 = up * y_force_scalar
return force
DebugDraw3D.draw_arrow(
to_global(wheel_center),
to_global(wheel_center + force / 1000),
Color.RED,
.2
)
car.apply_force(force, car.to_local(to_global(wheel_center)))
func apply_rolling_resistance() -> void:
if not is_colliding(): return
var normal: Vector3 = get_collision_normal()
var velocity: Vector3 = car.get_velocity_at_point(get_collision_point())
velocity -= normal * normal.dot(velocity)
var force: Vector3 = -rolling_resistance * velocity
var arrow_tail: Vector3 = to_global(get_wheel_center())
car.apply_force(force, car.to_local(get_collision_point()))
DebugDraw3D.draw_arrow(
arrow_tail,
arrow_tail + force,
Color.ORANGE,
.2
)
func apply_engine_force() -> void:
if not on_drivetrain: return
if not is_colliding(): return
var forwards: Vector3 = -global_basis.z
var torque: float = car.get_torque_per_wheel()
var force: Vector3 = forwards * torque / wheel_radius
var arrow_tail: Vector3 = to_global(get_wheel_center())
car.apply_force(force, car.to_local(get_collision_point()))
DebugDraw3D.draw_arrow(
arrow_tail,
arrow_tail + force / 250,
Color.BLUE,
.2
)
func get_wheel_center() -> Vector3:
var up: Vector3 = global_basis.y
var collision_point: Vector3 = to_local(get_collision_point())
return collision_point + (up * wheel_radius)