pr_assets

pr_assets is a repository of OpenRAVE resources used by the Personal Robotics Lab. Primarily, this includes a repository of meshes and KinBody XML specifications for objects commonly encountered by HERB and ADA.

Warning: The models in this package depend on features recently added to OpenRAVE 0.9. In particular, your version of OpenRAVE must support geometry groups in the .kinbody.xml format added in commit b032128.

Loading Models

This package uses the openrave_catkin package to automatically manage the OPENRAVE_DATA environment variable. This means that, once this package is built using catkin_make, you should be able to import any model in the data/ directory with a relative path. For example:

kinbody = env.ReadKinbodyURI('objects/pop_tarts.kinbody.xml')
env.Add(kinbody)

Model Creation Guidelines

We currently split models into two categories. Static objects in the environment (e.g. tables, chairs, shelves) are in the furniture directory. Any objects that can be grasped are in the objects directory. You are welcome to create additional categories if it seems appropriate to do so.

Naming Convention

We follow this naming convention for models of rigid bodies:

model_name.kinbody.xml: OpenRAVE KinBody specification
model_name_collision.stl: collision geometry (as small as possible)
model_name_visual.dae: visual geometry; medium resolution (< 500 kB)
model_name_visual_0.jpg: textures for visual geometry (< 500 kB)
model_name_scan.dae: raw model produced by the 3D scanner
model_name_scan_0.jpg: raw texture produced by the 3D model

Note that some models (e.g. un-textured objects, primitive collision geometry) may only require a subset of these files. Additionally, we do not have a strict naming convention for articulated bodies. Please try your best to stay consistent with the existing models.

Sphere Approximation

All objects should define a spheres geometry group that includes a conservative (i.e. over-approximation) decomposition of the object's collision geometry as a collection of one or more spheres. These spheres can be created in a .kinbody.xml file using the following syntax:

<!-- ... -->
<Geom type="sphere" group="spheres">
  <Translation>0 0 0</Translation>
  <Radius>0.1</Radius>
</Geom>
<!-- ... -->

The approximation is necessary to plan with CHOMP while the object is grasped. Specifying a non-conservative approximation may cause CHOMP to return infeasible trajectories.

Contributors

pr_assets was developed by the Personal Robotics Lab. The packaging and conventions listed above were developed collaboratively by Michael Koval and Aaron Walsman.