Mutable Links Discussion

[mpowelson]

@Levi-Armstrong and I had an online discussion about adding mutable links, and I wanted to type up some quick notes.

Use cases

• Frequently updated environmental information like an octree being updated from a sensor
• Some objects being tracked in an environment with a bounding box that gets updated.
• Others?

Thoughts/Notes

• It would be nice to generalize the problem such that all links can be modified and update flowed down quickly. Updating the size of a box should be very fast and shouldn't require removing and re-adding a link
• MoveIt has an octree in the planning scene. We could add a similar generic global octree that you can update with diffs.
• The Bullet octree implementation is probably not as fast as the FCL one. We might need to add a different implementation

General next steps

• Add an octree to the contact managers that always gets added if not null.
• Track diffs to the octree in the environment commands. This may not even be a link and will be highly optimized.
• Long term, consider also having a way to modify any link.