refactor pybullet/gym to allow instantiating environments directly from a pybullet install:

work-in-progress (need to add missing data files, fix paths etc)

example:

pip install pybullet
pip install gym

python
import gym
import pybullet
import pybullet_envs
env = gym.make("HumanoidBulletEnv-v0")

examples/pybullet/gym/pybullet_envs/bullet/racecar.py

@@ -0,0 +1,57 @@
+import pybullet as p
+import numpy as np
+import copy
+import math
+
+class Racecar:
+
+  def __init__(self, urdfRootPath='', timeStep=0.01):
+    self.urdfRootPath = urdfRootPath
+    self.timeStep = timeStep
+    self.reset()
+
+  def reset(self):
+    self.racecarUniqueId = p.loadURDF("racecar/racecar.urdf", [0,0,.2])
+    self.maxForce = 20
+    self.nMotors = 2
+    self.motorizedwheels=[2]
+    self.inactiveWheels = [3,5,7]
+    for wheel in self.inactiveWheels:
+      p.setJointMotorControl2(self.racecarUniqueId,wheel,p.VELOCITY_CONTROL,targetVelocity=0,force=0)
+
+    self.motorizedWheels = [2]
+    self.steeringLinks=[4,6]
+    self.speedMultiplier = 4.
+    
+
+  def getActionDimension(self):
+    return self.nMotors
+
+  def getObservationDimension(self):
+    return len(self.getObservation())
+
+  def getObservation(self):
+    observation = []
+    pos,orn=p.getBasePositionAndOrientation(self.racecarUniqueId)
+    
+    observation.extend(list(pos))
+    observation.extend(list(orn))
+    
+    return observation
+
+  def applyAction(self, motorCommands):
+    targetVelocity=motorCommands[0]*self.speedMultiplier
+    #print("targetVelocity")
+    #print(targetVelocity)
+    steeringAngle = motorCommands[1]
+    #print("steeringAngle")
+    #print(steeringAngle)
+    #print("maxForce")
+    #print(self.maxForce)
+    
+    
+    for motor in self.motorizedwheels:
+      p.setJointMotorControl2(self.racecarUniqueId,motor,p.VELOCITY_CONTROL,targetVelocity=targetVelocity,force=self.maxForce)    
+    for steer in self.steeringLinks:
+      p.setJointMotorControl2(self.racecarUniqueId,steer,p.POSITION_CONTROL,targetPosition=steeringAngle)
+