## underwater

Post links to your CoppeliaSim videos, scenes and models
Aws Ahmad
Posts: 1
Joined: 17 Nov 2020, 08:36

### underwater

https://www.youtube.com/watch?v=ytKzx2Xsukk

Hello
I have designed undulating robot
I need help to add water effect
and i want to sumulate robot fin move
https://drive.google.com/file/d/1xriDLN ... sp=sharing

coppelia
Site Admin
Posts: 8583
Joined: 14 Dec 2012, 00:25

### Re: underwater

Hello,

in order to simulate the effect of the water (e.g. buoyancy and drag), you'll have to emulate that yourself. Typically, you'll add a vertical force that is proportional to the immersion depth of the robot in the water. Or a constant force if the object is underwater at equilibrium. For the effect of fins, add a drag force that is inversely proportional to the body velocity. I'd use only the velocity that is normal to the fins, in order to let it glide along the fins' surface.
Use sim.addForceAndTorque and sim.getVelocity. See how the demo model from the library models/robots/mobile/ACMR-5.ttm was made (try to place it outside of the floor, and it will evolve as if in water).

Cheers