Top Down Car Driving for Gym

A custom gym environment for a top down drifting game

Requirements:

Python 3.8+

Install using the pip package:

pip install gym-CarDrifting2D

Here is an example with random actions:

import gym
import gym_Drifting2D
import random

env = gym.make("CarDrifting2D-v0", drag=0.9, power=1, turnSpeed=0.04, angularDrag=0.6, multiInputs=False, showGates=False, constantAccel=False)
# Parameter Definitions:
# Drag, how much the car skids, the higher the more skid
# power, how fast the car accelerates
# turnSpeed, how fast the car turns
# angularDrag, how much the car spins, the higher the more spin
# Multi Inputs means the agent can go both forward/backward AND left or right simultaneously
# Show Gates is to show the reward gates
# constant accel is to accelerate constantly
env.reset()

num_states = env.states
num_actions = env.actions

while True:
    action = random.randint(0, num_actions)
    state, reward, done, _ = env.step(action)
    if done:
        env.reset()
    env.render()

The agent has a total of 9 actions which are:

1. Forward

2. Backward

3. Left

4. Right

5. Forward Left

6. Forward Right

7. Backward Left

8. Backward Right

9. Do nothing

There are numerous hidden Reward Gates around the track that the agent must cross to get a reward

The agent will receive a constant negative reward of -0.01 unless it either crosses a reward gate which will result in +1 reward or crashes into the wall which will result a -1 reward and cause the done flag to become True indicating that you should call env.reset()

For those interested in the game Physics!

The agent has a vector called pos which stores the car's location, a vector called vel which stores the car's velocity along with a variable called drag which is it's drag. It has a variable called power which is how fast the car accelerates and 3 more variables which are angularVel which is the Angular Velocity angularDrag which is the Angular Drag and turnSpeed which is the turning speed. It also has one more variable called angle which is the angle of the car affected by angularVel.

self.pos = [650, 200]
self.velX = 0
self.velY = 0
self.drag = drag
self.angularVel = 0.0
self.angularDrag = angularDrag
self.power = power
self.turnSpeed = turnSpeed
self.angle = math.radians(-90)

Each step the following operations are executed

self.pos[0] += self.velX
self.pos[1] += self.velY

self.velX *= self.drag
self.velY *= self.drag
self.angle += self.angularVel
self.angularVel *= self.angularDrag

And here are the control functions:

def acc(self):
    self.velX += math.sin(self.angle) * self.power
    self.velY += math.cos(self.angle) * self.power

    if (self.velX > 10):
        self.velX = 10

    if (self.velY > 10):
        self.velY = 10

def decc(self):
    self.velX -= math.sin(self.angle) * self.power
    self.velY -= math.cos(self.angle) * self.power

    if (self.velX < -10):
        self.velX = -10

    if (self.velY < -10):
        self.velY = -10

def right(self):
    self.angularVel += self.turnSpeed

def left(self):
    self.angularVel -= self.turnSpeed

Enjoy! And don't forget to leave feedback on improvements or bugs!