[question] Does DART support ray collisions?

[romulogcerqueira]

Hi,

I'm interested in confirming if DART supports ray collisions. I could not find any mention in the DART documentation, just a few documentation code snippets at OdeCollisionDetector.hpp and CollisionDetector.cpp.

Thanks in advance.

[jslee02]

Yes, DART does support ray collisions via the Bullet backend. You may find the CollisionDetector::raycast() and CollisionGroup::raycast() APIs useful. Although we don't have a C++ example at the moment, we do have a Python example that could provide some idea on how to use these C++ APIs.

[romulogcerqueira]

Thanks for your reply, @jslee02.

My question was related to the missing ray collision feature in gz-sim, where DART is the default physics engine. There is an open issue for that.

Do you have any recommendations for using the Bullet backend in gz-physics?

Alternatively, can we use ConeShape to mimic the ray collision? Does DART present the contact points/closest points for a collision between cones and 3D arbitrary in the scene?

[jslee02]

I haven't followed the recent changes in gz-sim recently, but it appears that the Bullet backend in gazebo-physics is already supported, which can be configured through SDF (<collision_detector>). I would recommend to consult with the Gazebo community for a more precise answer or support because I might have incorrect or outdated information.

Using ConeShape or any other suitable collision shape (with appropriate dimensions) that meets your requirements makes sense to me. FYI, ConeShape is currently only supported by the Bullet and ODE backends in DART.