While mechanical simulation software simulates how a single beam bends or transfers heat, 3D dynamics simulation software is a physics engine that simulates the movement and collision of multiple rigid bodies, e.g., a hexapod with four actuating legs on a flat surface.

We currently have no good 3D dynamics simulation setup.

In the past, we've used V-REP, which has now become CoppeliaSim.

However, we may move toward using Gazebo, which has fewer licensing restrictions, may be slightly longer-lived, does not have as much polish, but can probably more easily handle swarms of robots.