Michael Sherman

Since hydroelastics has always been presented as "experimental" up to now, do we really need to deprecate this? We haven't been deprecating hydroelastic API changes.

A RollPitchYawJoint would be a great addition. BTW you can produce that effect today with three revolute and three prismatic joints and a few intermediate massless bodies.

From f2f discussion: - better workaround: use BallRpyJoint plus x-y-z prismatics. - @amcastro-tri says he'll push the new 6 dof joint. For consistency with the ball I think it should...

For consistency it should be FloatingRpyJoint, or we would have to rename BallRpyJoint -> RpyBallJoint. But I think FloatingRpyJoint and BallRpyJoint are marginally better because they start with the joint...

No, Joe is planning to add a 6-dof joint that uses a quaternion. Would be good to have the Rpy option also but that isn't needed for Joe's purpose.

FYI -- If you want to emulate the future FloatingRpyJoint exactly, put the BallRpyJoint first, followed by three PrismaticJoints (with two massless links in between). Caveat: the BallRpyJoint doesn't allow...

Any thoughts / progress on this, @joemasterjohn ?

The runtime cost is just the check of the "already initialized" flag which doesn't require a lock. That still seems like the wrong mechanism here though. We shouldn't have to...

I'm trying to figure out what would be the right fix for this, which I feel didn't work as the user (Russ) expected. The [current documentation for Initialize()](https://drake.mit.edu/doxygen_cxx/classdrake_1_1systems_1_1_simulator.html#a98b1050f09da390896f964fb7a892391) has this...

I'm not in favor of printing a message because I don't think we have a mechanism in Drake to guarantee that the user will see it. Do we have any...