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/scene_abstract.py

@@ -0,0 +1,76 @@
+import sys, os
+sys.path.append(os.path.dirname(__file__))
+import pybullet as p
+
+import gym
+
+
+class Scene:
+    "A base class for single- and multiplayer scenes"
+
+    def __init__(self, gravity, timestep, frame_skip):
+        self.np_random, seed = gym.utils.seeding.np_random(None)
+        self.timestep = timestep
+        self.frame_skip = frame_skip
+        self.dt = self.timestep * self.frame_skip
+        self.cpp_world = World(gravity, timestep)
+        #self.cpp_world.set_glsl_path(os.path.join(os.path.dirname(__file__), "cpp-household/glsl"))
+
+        #self.big_caption = self.cpp_world.test_window_big_caption  # that's a function you can call
+        #self.console_print = self.cpp_world.test_window_print      # this too
+
+        self.test_window_still_open = True  # or never opened
+        self.human_render_detected = False  # if user wants render("human"), we open test window
+
+        self.multiplayer_robots = {}
+
+    def test_window(self):
+        "Call this function every frame, to see what's going on. Not necessary in learning."
+        self.human_render_detected = True
+        return self.test_window_still_open
+
+    def actor_introduce(self, robot):
+        "Usually after scene reset"
+        if not self.multiplayer: return
+        self.multiplayer_robots[robot.player_n] = robot
+
+    def actor_is_active(self, robot):
+        """
+        Used by robots to see if they are free to exclusiveley put their HUD on the test window.
+        Later can be used for click-focus robots.
+        """
+        return not self.multiplayer
+
+    def episode_restart(self):
+        "This function gets overridden by specific scene, to reset specific objects into their start positions"
+        self.cpp_world.clean_everything()
+        #self.cpp_world.test_window_history_reset()
+
+    def global_step(self):
+        """
+        The idea is: apply motor torques for all robots, then call global_step(), then collect
+        observations from robots using step() with the same action.
+        """
+        #if self.human_render_detected:
+        #    self.test_window_still_open = self.cpp_world.test_window()
+        self.cpp_world.step(self.frame_skip)
+
+class SingleRobotEmptyScene(Scene):
+    multiplayer = False  # this class is used "as is" for InvertedPendulum, Reacher
+
+class World:
+
+	def __init__(self, gravity, timestep):
+		self.gravity = gravity
+		self.timestep = timestep
+		self.clean_everything()
+
+	def clean_everything(self):
+		p.resetSimulation()
+		p.setGravity(0, 0, -self.gravity)
+		p.setPhysicsEngineParameter(fixedTimeStep=self.timestep, numSolverIterations=5, numSubSteps=2)
+
+	def step(self, frame_skip):
+		p.stepSimulation()
+
+