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eleramp / pybullet-object-models

Collection of object models compatible with pybullet simulator https://github.com/bulletphysics/bullet3/tree/master/examples/pybullet
GNU Lesser General Public License v2.1
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Determining the inertial properties #4

Open richardrl opened 2 years ago

richardrl commented 2 years ago

How did you determine the inertial properties for the URDFs?

eleramp commented 2 years ago

HI! For a good estimation you can use MeshLab. Open the mesh file in MeshLab. To compute the inertial parameters, you first need to display the Layers dialog - View->Show Layer Dialog. Next, command MeshLab to compute the inertial parameters. Choose Filters->Quality Measure and Computations->Compute Geometric Measures from the menu. The lower part of the Layers dialog should now show some info about the inertial measures. You get something like:

Mesh Bounding Box Size 2.000000 2.000000 2.000000
Mesh Bounding Box Diag 3.464102
Mesh Volume is 4.094867
Mesh Surface is 12.425012
Thin shell barycenter -0.000000 -0.000000 -0.000000
Center of Mass is -0.000000 0.000000 -0.000000
Inertia Tensor is :
| 1.617916 -0.000000 0.000000 |
| -0.000000 1.604620 -0.000000 |
| 0.000000 -0.000000 1.617916 |
Principal axes are :
| 0.000000 1.000000 0.000000 |
| -0.711101 -0.000000 0.703089 |
| -0.703089 0.000000 -0.711101 |
axis momenta are :
| 1.604620 1.617916 1.617916 |