BEPUphysics

i saw someone using this physic on his game, and looked really nice, soo me as a beginner, what can this assed do or wahts the difference betwen the unity

and how do i nstall this just to try it out

That's a pretty broad question, but at a high level, it's a rigid body physics engine, and it's very speedy. It's also important to note that it is not beginner friendly- the API is very low level and aimed at advanced users who want zero overhead access. If you don't have experience with that sort of thing, or with physics engines in general, it's not a very good place to start.

You can grab the whole repo, demos included, off of github: https://github.com/bepu/bepuphysics2

If you're a unity developer, be aware that unity's runtime does not like bepuphysics v2 very much: viewtopic.php?f=9&t=2528

The most recent versions can run it without crashing, but the performance can be thousands of times worse than on CoreCLR in some cases. I'd recommend holding off on using it until unity's runtime can handle it, or use it only in non-unity processes.

dosent there exit a tutorial?

im intresting in this becuase th one video i saw the character could move in a bouncy ship, and when i asked him how he done that he just replyed hes using this physics, becuase making the character walking on a bouncing ship is really hard

The github repo contains a demos application with dozens of examples and documentation. For example: https://github.com/bepu/bepuphysics2/bl ... Started.md

There isn't any documentation or tutorial targeting users new to game development, physics engines, or the involved math, though.