How to implement fin/thruster dynamics

[jlack1987]

Intro

Hi, interested in potentially using mujoco for subsea vehicle simulations

My setup

Mujoco 3.3.0, Ubuntu 24.04

My question

I'm interested in simulating subsea vehicles and in that I'd like to be able to add things like,

• Buoyancy/Drag
• Thruster model(simple quadratic velocity -> thrust)
• Fin, force/moment changes based on fin angle

I'm sure this stuff is possible, but it hasn't been obvious to me based on the documentation. Is there a recommended way to add these type of things?

Minimal model and/or code that explain my question

No response

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.

[jlack1987]

It looks like perhaps the mj_applyFT could be used to apply arbitrary forces to a body and I could perhaps use that to apply whatever forces I want. Does this seem like a reasonable way to implement it?