Implementations relate to medical simulations for medical procedure training. In some implementations, a system includes a simulation processing component including at least one processor and which generates a virtual environment using position signals that describe at least one of a position and a configuration of a physical surgical instrument relative to a physical surgical site. The simulation processing component updates the virtual environment according to changes in the position signals and according to control signals corresponding to inputs by a user of the system. The updating includes moving a virtual surgical instrument within the virtual environment, where an interaction of the virtual surgical instrument with a virtual surgical site is defined at least partly by a physical relationship between the physical surgical instrument and the physical surgical site. The simulation processing component outputs a representation of a simulation state signal indicative of a current state of the virtual environment.
