AnyObjectReceptacle

[aclegg3]

Motivation and Context

This PR introduces the AnyObjectReceptacle. This allows any object in the simulation to be used as a Receptacle by implementing the Receptacle API in a generic way:

• The top surface of the global bounding box of the object in its current state is used as the sampling region for snap_down placements.
• Can support RigidObject, ArticulatedObject, ArticulatedLink
• Can be added to the world at any time
• Can debug draw itself
• supports a required "up" direction (Y+ axis) preventing placement when the object is upside down or sideways

Future Improvements/iterative work:

• TODO: optionally disable "up" direction to support stacking objects in any orientation
• TODO: option to pre-generate a discrete set of candidate points in object local space instead of using the global AABB.
• TODO: bounds attribute cannot be computed because Receptacle does not expect access to sim for this.
• TODO: transform caching and dirty check could prevent wasted cycles when the object has not moved between queries.

How Has This Been Tested

Added a unit test.

Local testing in example app. The video below takes place in a ReplicaCAD scene. Pre-configured AABBReceptacles already exist in the scene. Some objects do not have Receptacles configured. When the user clicks such an object, an AnyObjectReceptacle is added. This can then be used to sample snap_down placements.

Notice that these placements are not very good (especially with dynamic simulation stability). That's why we annotate Receptacles instead of using this approach in general. However, this is better than nothing and should serve for kinematic use cases.

any_object_receptacle-2024-04-25_15.38.22.mp4

Types of changes

• [Development] A pull request that add new features to the habitat-lab task and environment codebase. Development Pull Requests must be small (less that 500 lines of code change), have unit testing, very extensive documentation and examples. These are typically new tasks, environments, sensors, etc... The review process for these Pull Request is longer because these changes will be maintained by our core team of developers, so make sure your changes are easy to understand!

Checklist

• My code follows the code style of this project.
• I have updated the documentation if required.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes if required.

[rutadesai]

LGTM! Excited to integrate this when ready :)