Water simulation

[amirhnourian]

Thank you for sharing this impressive work modeled in Isaac Sim. I really appreciate the effort put into the simulation.

However, I noticed that some of the USD assets shown in the documentation appear to be missing from the repository—I wasn’t able to locate them despite searching thoroughly.

Additionally, I’m a bit unclear about how the drag, buoyancy, and other physical forces were implemented in your simulation. You mentioned adding them manually, but as far as I know, Isaac Sim supports particle-based water simulation along with built-in drag, contact, and buoyancy force calculations. Could you kindly clarify why you chose a manual approach over the built-in features?

[haoyuma2002814]

Hi.

Some environment assets come with license thus it's difficult for us to directly disperse them in here.
However, users can got to SketchFab\unreal fab to find those environments. (We find those assets from there, too)

As for underwater dynamics, it is an ongoing research project in our lab and users can stay tuned and wait for future OceanSim updates.

Particle based water simulation built in Isaac Sim only guarantees visual fidelity (as it's motivated from the task of manipulators handling objects containing liquid), therefore we are not going to use that approach. Moreover, simulating large scale fluid dynamics is very compuationally intensive, which greatly impacts real time performance and fast SDG.

[haoyuma2002814]

Thank you for interest.

We do need people with specialty on marine robot dynamics to develop new features on OceanSim.

We have an early exploration of using fossen dynamics in Isaac Sim, simply by using the output of a python ODE solver that solves the fossen's equation and override the output (pos/vel, etc) onto the robot mesh in the simulator.

We are either expecting people can build dynamic modules such as propellers so that people can assemble their AUVs in oceansim, or we are expecting we can derive an accurate fossen models for one type of robots (BlueROV for instance), then verify its dynamical accuracy by bench marking using sysid.

Here is my email: mahaoyu@umich.edu. And feel free to email me if you have difficulty understanding the codebase.

[kushagra77]

Hi @haoyuma2002814 regarding the usd assets from sketch fab/unreal fab. any chance you can put the link to any of them here? I am trying to recreate the pylon environment for a project and it would help to get that environment instead of remaking it from scratch.

[haoyuma2002814]

@kushagra77
Hi, here is the mall scene : https://sketchfab.com/3d-models/ruins-of-the-underwater-shopping-mall-30a20007064845c9928519da4aefefde

Let me know if you find problems when converting this to usd format.

[kushagra77]

thanks for that, any chance I can get the scene with the underwater pillars instead? That is much more useful to me.

[haoyuma2002814]

Sorry for that scene, sketchfab seems to pull that off from their market.

But you can find many similar ones from either : https://sketchfab.com/search?features=downloadable&q=pier&type=models

or https://www.fab.com/search?q=pier