update parsers/simulators + add simulator example

examples/simulators/README.md

@@ -22,6 +22,9 @@ joint position values that were returned by the Bullet simulator on the correspo
 values from the ROS topics and change them in the simulator. This works with the `bullet_ros_publisher.py` code 
 presented above. By moving the robot with your mouse in the publisher version, you will see the robot in this 
 subscriber version moves in accordance with. This can be useful if you have access to the real platform as well.
+4. `simulators.py`: example which loads few primitive shapes and the ANYmal robot using a simulator among `Bullet`, 
+`Mujoco`, `Raisim`, and `Dart`. Only the line `sim = <SimulatorName>(render=True)` needs to be changed. Note that 
+the integration of these other simulators is ongoing.
 
 Later, a `ROS`/`ROS_RBDL` "simulator" (without passing by a real simulator like `Bullet`) will allow you to make 
 your code works on a real platform using ROS without changing any other lines of code. This is one of the big 

examples/simulators/simulators.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+"""Simulator tests.
+
+Example on how to load different things with the simulators. This example is still in an experimental phase. For
+now, only Bullet is fully-supported. We are working on the other ones, especially the Mujoco simulator.
+- Bullet: OK
+- Raisim: OK  (todo: for collision bodies, it only accepts OBJ files)
+- MuJoCo: OK  (todo: control still missing)
+- DART: OK, but capsules don't have collision shapes... (todo: fix some URDFs)
+- VREP: Not implemented yet + problem when importing PyRep with pybullet. Also, need to figure out how to call the
+  'loadURDF' plugin.
+- Isaac: not available yet.
+"""
+
+import os
+from itertools import count
+
+from pyrobolearn.simulators.bullet import Bullet
+from pyrobolearn.simulators.raisim import Raisim
+from pyrobolearn.simulators.dart import Dart
+from pyrobolearn.simulators.mujoco import Mujoco
+# from pyrobolearn.simulators.vrep import VREP  # Problem when importing PyRep with Pybullet
+# from pyrobolearn.simulators.isaac import Isaac  # Not available yet
+
+
+sim = Bullet(render=True)
+# sim = Raisim(render=True)
+# sim = Dart(render=True)
+# sim = Mujoco(render=True)
+# sim = VREP(render=True)
+# sim = Isaac(render=True)
+print("Gravity: {}".format(sim.get_gravity()))
+
+# load floor
+floor = sim.load_floor(dimension=20)
+
+# create box
+box = sim.create_primitive_object(sim.GEOM_BOX, position=(0, 0, 2), mass=1, rgba_color=(1, 0, 0, 1))
+sphere = sim.create_primitive_object(sim.GEOM_SPHERE, position=(2, 2, 2), mass=1, rgba_color=(0, 1, 0, 1))
+cylinder = sim.create_primitive_object(sim.GEOM_CYLINDER, position=(0, 2, 2), mass=1)
+capsule = sim.create_primitive_object(sim.GEOM_CAPSULE, position=(0, -2, 2), mass=1, rgba_color=(0, 0, 1, 1),
+                                      radius=0.5, height=0.5)
+
+# load robot
+urdf_path = os.path.dirname(os.path.abspath(__file__)) + '/../../pyrobolearn/robots/urdfs/'
+# path = urdf_path + 'rrbot/rrbot.urdf'
+# path = urdf_path + 'jaco/jaco.urdf'
+# path = urdf_path + 'kuka/kuka_iiwa/iiwa14.urdf'
+# path = urdf_path + 'hyq2max/hyq2max.urdf'
+path = urdf_path + 'anymal/anymal.urdf'
+# path = urdf_path + 'centauro/centauro_stick.urdf'
+
+robot = sim.load_urdf(path, position=(3, -3, 2), use_fixed_base=False)
+
+# perform step
+for t in count():
+    sim.step(sleep_time=sim.dt)