Change parameters during robot learning using simulators (Webots, Gazebo, etc)

Question

I am searching a simulator for my robot learning research.

In the learning process, I need to change parameters of both environment (friction coefficients, terrain height in the world) and robot itself (mass, inertia).

How can simulators like Gazebo and Webots realize it?

(another problem: bisides physics engine, I also need visual reality for computer-vision-aided algorithms. Is there any simulator that could provide both functions? )

Answer 1

Webots allows you from a supervisor program to easily change any parameter of a simulation (including friction coefficients) while it is running. Moreover it has a VR interface. I don't know about Gazebo.