Hello!

I found a script for simulating simple car physics and adapted it to my liking.

The problem is that I can't find a proper way to have the car collide with a staticbody and in turn change its velocity accordingly. Instead it keeps its speed, slides from the staticbody and continues on its way with the same speed.

I reckon I have to do something with whatever `move_and_slide(move_vector)` returns, but I just can't seem to figure it out. I'm so close to having the perfect car simulation I need for my game.

``````extends KinematicBody2D

const DEBUG = true

export var max_speed_forward = 2000
export var max_speed_backwards = 500
export var accel := 1.0         # acceleration
export var momentum = 0.3     # momentum
export var deaccel_brake = 2 # brake force

var current_direction = Vector2(0, -1)

export var rotation_speed := 1.0

var current_speed = 0
var current_turn = 0

var handling_level = 0
var acceleration_level = 0
var topspeed_level = 0

var real_speed = 0

func perpendicular_vector(vec: Vector2):
return Vector2(vec.y, -vec.x)

func _physics_process(delta):
# Change forward velocity based on up and down input
if Input.is_action_pressed("brake"):
if current_speed < 0: # When we go forward
current_speed += deaccel_brake * delta
elif current_speed < 1: # When we go backwards
current_speed += accel * delta
elif Input.is_action_pressed("accelerate"):
if current_speed > -1:
current_speed -= accel * delta
else: # When player isn't holding anything, deaccelerate
if current_speed < -0.01: # When we go forward
current_speed += momentum * delta
elif current_speed > 0.01: # When we go backwards
current_speed -= momentum * delta
else: # STOP
current_speed = 0

# Setting the current turn direction
if Input.is_action_pressed("steer_left"):
current_turn = delta
elif Input.is_action_pressed("steer_right"):
current_turn = -delta
else:
current_turn = 0

if DEBUG:
if Input.is_action_just_pressed("up_handling"):
handling_level += 1
set_steering_angle()
if Input.is_action_just_pressed("down_handling"):
handling_level -= 1
set_steering_angle()
if Input.is_action_just_pressed("up_acceleration"):
acceleration_level += 1
set_acceleration()
if Input.is_action_just_pressed("down_acceleration"):
acceleration_level -= 1
set_acceleration()
if Input.is_action_just_pressed("up_topspeed"):
topspeed_level += 1
set_topspeed()
if Input.is_action_just_pressed("down_topspeed"):
topspeed_level -= 1
set_topspeed()

# Add a scaled down perpendicular vector of current dirrection to the direction.
# This will result in changing the direction vector each frame when player is holding
# right/left keys
# Multypling by current speed is optional (This way you prevent turning around on one place)
current_direction += perpendicular_vector(current_direction) * current_turn * rotation_speed * -current_speed

# Normalize the vector, so the direction is preserved but size remains the same.
# This prevents acceleration bug
current_direction = current_direction.normalized()

# Visual rotation of our kinematic body.

# Application of the result movement
var move_vector = current_direction * -current_speed * delta
if current_speed > 0:
move_vector *= max_speed_backwards
real_speed = (current_speed * -max_speed_backwards) / 50

else:
move_vector *= max_speed_forward
real_speed = (current_speed * max_speed_forward*-1) / 50

move_and_slide(move_vector)

func set_steering_angle():
rotation_speed = 1 + handling_level * 0.5

func set_acceleration():
accel = 1 + acceleration_level * 0.25

func set_topspeed():
max_speed_forward = 2000 + topspeed_level * 1000
``````
Godot version v3.3.3
in Engine
edited