Re: stepSimulation() not equivalent to setRealTimeSimulation(1)

2020-04-07T19:44:26+00:00

Testing here there is no difference between stepSimulation and setRealTimeSimulation, both show instable motion due to a degenerate urdf file.

Those are urdf files with degenerate values. Avoid too small mass (keep it either 0 or in range 0.01 to 100 or so)
avoid large rpy angles, don't use collision shapes with extreme small radius (use 0.05 smallest for a start)

Here is a working version:

Code:

Statistics: Posted by Erwin Coumans — Tue Apr 07, 2020 7:44 pm

stepSimulation() not equivalent to setRealTimeSimulation(1)

2020-04-03T02:31:55+00:00

I want to control a procedurally generated robot. Consider the following code:

Code:

import timeimport pybullet as pimport pybullet_dataimport sysphysicsClient = p.connect(p.GUI)p.setPhysicsEngineParameter(enableFileCaching=0)p.setAdditionalSearchPath(pybullet_data.getDataPath())p.resetSimulation()p.setGravity(0, 0, -10)planeId = p.loadURDF("plane.urdf")robot = p.loadURDF(sys.argv[1], [0, 0, 2])p.setRealTimeSimulation(1)for t in range(200000):    p.getKeyboardEvents()p.resetSimulation()p.setGravity(0, 0, -10)planeId = p.loadURDF("plane.urdf")robot = p.loadURDF(sys.argv[1], [0, 0, 2])p.setRealTimeSimulation(0)for t in range(200000):    p.stepSimulation()    time.sleep(1. / 240.)p.disconnect()

The first half runs fine. The second half, my URDF file goes crazy and flies off. Example URDF files that have this behaviour:
https://raw.githubusercontent.com/avand ... ter/2.urdf
https://raw.githubusercontent.com/avand ... ter/1.urdf

Am I misunderstanding something here? What is going on? Why are the two so different?

Edit:

I tried this code using some of the sample URDF files provided and they seem to work alright. There must be some issue in processing the physics of my URDF files.

Statistics: Posted by avandekleut — Fri Apr 03, 2020 2:31 am

Real-Time Physics Simulation Forum

Re: stepSimulation() not equivalent to setRealTimeSimulation(1)

stepSimulation() not equivalent to setRealTimeSimulation(1)