move pybullet.connect into the Gym environment.

If you like to enable rendering, call the env.render(mode="human") before calling the first env.reset

examples/pybullet/gym/pybullet_envs/gym_locomotion_envs.py

@@ -1,12 +1,15 @@
 from .scene_stadium import SinglePlayerStadiumScene
 from .env_bases import MJCFBaseBulletEnv
 import numpy as np
+import pybullet as p
 from robot_locomotors import Hopper, Walker2D, HalfCheetah, Ant, Humanoid
 
 
 class WalkerBaseBulletEnv(MJCFBaseBulletEnv):
-	def __init__(self, robot):
-		MJCFBaseBulletEnv.__init__(self, robot)
+	def __init__(self, robot, render=False):
+		print("WalkerBase::__init__")
+		MJCFBaseBulletEnv.__init__(self, robot, render)
+		
 		self.camera_x = 0
 		self.walk_target_x = 1e3  # kilometer away
 		self.walk_target_y = 0
@@ -16,11 +19,15 @@ class WalkerBaseBulletEnv(MJCFBaseBulletEnv):
 		return self.stadium_scene
 
 	def _reset(self):
+		
 		r = MJCFBaseBulletEnv._reset(self)
+		p.configureDebugVisualizer(p.COV_ENABLE_RENDERING,0)
+
 		self.parts, self.jdict, self.ordered_joints, self.robot_body = self.robot.addToScene(
 			self.stadium_scene.ground_plane_mjcf)
 		self.ground_ids = set([(self.parts[f].bodies[self.parts[f].bodyIndex], self.parts[f].bodyPartIndex) for f in
 							   self.foot_ground_object_names])
+		p.configureDebugVisualizer(p.COV_ENABLE_RENDERING,1)
 		return r
 
 	def move_robot(self, init_x, init_y, init_z):