Real-Time Physics Simulation Forum

Hello

I am trying to load an SDF file into the pybullet environment. However, it comes up with the
"error: Cannot load SDF file."
My code is as follows:

import pybullet as p
import time
import pybullet_data
physicsClient = p.connect(p.GUI)
p.setAdditionalSearchPath(pybullet_data.getDataPath())
p.setGravity(0,0,-10)
planeId = p.loadSDF("plane_stadium.sdf")
boxId = p.loadSDF("free_loop.sdf")

for i in range (3000):
p.stepSimulation()
time.sleep(1./240.)
p.disconnect()

I have made sure that the files are in the correct directory.
The free_loop.sdf file has a closed loop structure ( wherein the links are connected in a loop)
I wonder, if it is not possible to load an SDF file into pybullet which has a closed structure (unlike the tree structure of URDF format)?
Is there any easy workaround to this? Any example would be appreciated.
Thank you!

SDF and URDF files need to be tree structure/ open loop.

PyBullet provides user constraints to close loops.
See our Minitaur example how to add such constraint.
https://github.com/bulletphysics/bullet ... ur.py#L391
See createConstraint in the examples and PyBullet Quickstart Guide.
https://docs.google.com/document/d/10sX ... e70wns7io3