text: #!/usr/bin/env python
  from gazebo_msgs.msg import ODEPhysics
  from geometry_msgs.msg import Vector3
  from gazebo_msgs.srv import SetPhysicsProperties
  from std_msgs.msg import Float64
  import rospy
  
  set_gravity = rospy.ServiceProxy('/gazebo/set_physics_properties', SetPhysicsProperties)
  
  time_step = Float64(0.003) # default: 0.001
  max_update_rate = Float64(300.0) # default: 1000.0
  gravity = Vector3()
  gravity.x = 0.0
  gravity.y = 0.0
  gravity.z = -9.8
  ode_config = ODEPhysics()
  ode_config.auto_disable_bodies = False
  ode_config.sor_pgs_precon_iters = 0
  ode_config.sor_pgs_iters = 50
  ode_config.sor_pgs_w = 1.3
  ode_config.sor_pgs_rms_error_tol = 0.0
  ode_config.contact_surface_layer = 0.001
  ode_config.contact_max_correcting_vel = 50.0 # default: 100.0
  ode_config.cfm = 0.0
  ode_config.erp = 0.2
  ode_config.max_contacts = 20
  print "Changing gazebo properties."
  set_gravity(time_step.data, max_update_rate.data, gravity, ode_config)
  