[multibody] Use ContactResults for hydro forces in discrete plant unit test.

RobotLocomotion / drake

Model-based design and verification for robotics.

https://drake.mit.edu

Other

3.17k stars 1.24k forks source link

[multibody] Use ContactResults for hydro forces in discrete plant unit test. #21539

Closed joemasterjohn closed 3 weeks ago

joemasterjohn commented 3 weeks ago

Per this slack conversation and related to #21533.

Replaces call to EvalHydroelasticContactForces() (which will be made continuous plant only in #21533) in a unit test using a discrete plant. Instead the total hydro contact force acting on the body is calculated using the forces reported by ContactResults.

This change is