wx-b / pybullet-blender-recorder

Blender pyBullet Simulation Importer

This Blender plugin + python script allows you to easily import pyBullet simulations into Blender for visualizations.

Tested on Ubuntu 18.04.5 with Blender 2.83.3.

Setup

Installing the Blender plugin

Make sure Blender is installed

sudo snap install blender --classic

Open up Blender, go to Edit > Preferences > Add-ons and click [Install...].

Navigate to and import pyBulletSimImporter.py. Make sure the newly added PyBulletSimImporter add-on is enabled.

You should see an Animation tab to the right of the screen, where the UI for the importer is.

Usage

Recording a pyBullet Simulation

PyBulletRecorder track poses of individual links in pyBullet simulations along with their mesh path (taken from the URDF file), then save the animation out into a pickle file. PyBulletSimImporter consumes these pickle files, import the corresponding meshes, then animate those links with pose keyframes.

To record a pyBullet simulation, checkout demo.py

from pyBulletSimRecorder import PyBulletRecorder
import pybullet as p
import pybullet_data

# Setup pyBullet
p.connect(p.GUI)
p.setAdditionalSearchPath(pybullet_data.getDataPath())
p.setRealTimeSimulation(0)
p.setGravity(0, 0, -9.81)
p.loadURDF('plane.urdf')

recorder = PyBulletRecorder()
urdf_path = 'assets/power_drill/power_drill.urdf'
body_id = p.loadURDF(
    fileName=urdf_path,
    basePosition=(0, 0, 0.4),
    baseOrientation=(0.4, 0.3, 0.2, 0.1))

# 1. Tell recorder to track a pybullet object
recorder.register_object(body_id, urdf_path)
for _ in range(500):
    p.stepSimulation()
    # 2. Take a snap shot of all registered link poses
    recorder.add_keyframe()
# 3. Dump simulation to a pickle file
recorder.save('demo.pkl')

Importing a pyBullet Simulation to Blender

In the PyBulletSimImporter panel of the Animation tab in Blender, click on [Import simulation]. Navigate to and select the simulation pickle file you want to import.

Notes:

• If the simulation is large (i.e: many registered pyBullet objects, many 1000s of time steps,...), it might take Blender a while to import. Blender will freeze while it's importing. This is normal.
• You can import multiple pickle files at once into Blender, and they will each be organized under their own Blender collection.