Real-Time Physics Simulation Forum

Re: Simple boat buoyancy demo

2021-11-15T09:02:43+00:00

interesting！

Statistics: Posted by wanglei — Mon Nov 15, 2021 9:02 am

Re: Simple boat buoyancy demo

2021-03-10T07:00:13+00:00

I'm happy to follow this up, if nobody else cares to, and hi, Erwin!

Statistics: Posted by Leith — Wed Mar 10, 2021 7:00 am

Re: Simple boat buoyancy demo

2013-11-04T15:43:41+00:00

Considering his last visit to the forum was 2 years ago, you might have to be contented with his explanation instead of his source.

I don´t realy expected the topicstarter to give me the sorces, but may be the sources, even posible modified, are avaible somewhere and someone can say where to find them.

Statistics: Posted by gtafan — Mon Nov 04, 2013 3:43 pm

Re: Simple boat buoyancy demo

2013-11-04T15:13:29+00:00

Considering his last visit to the forum was 2 years ago, you might have to be contented with his explanation instead of his source.

Statistics: Posted by c6burns — Mon Nov 04, 2013 3:13 pm

Re: Simple boat buoyancy demo

2013-11-04T14:58:57+00:00

I would also like to see the sorcecode of this boat buoyancy demo.

Statistics: Posted by gtafan — Mon Nov 04, 2013 2:58 pm

Re: Simple boat buoyancy demo

2010-08-18T13:23:07+00:00

Could anybody send me a sample code on how to proceed to make a similar sample as shown by robagar?
I would like to use OgreBullet framework for making this.

Thanks in advance.

Statistics: Posted by jinij123 — Wed Aug 18, 2010 1:23 pm

Re: Simple boat buoyancy demo

2010-06-22T13:59:15+00:00

my boat now has a sail

http://www.youtube.com/watch?v=aVnHEcFVyp0

Statistics: Posted by robagar — Tue Jun 22, 2010 1:59 pm

Re: Simple boat buoyancy demo

2010-06-13T07:12:22+00:00

Thank you for your explanation !

Statistics: Posted by Flix — Sun Jun 13, 2010 7:12 am

Re: Simple boat buoyancy demo

2010-06-11T08:20:03+00:00

Cheers!

The floats are not real Bullet bodies - they are imaginary things attached to points on my boat object.

Code:

boat  + btRigidBody  + Ogre renderable  + floats

But yes, in the timestep the each float tests the water level at their position, then applies a force to the boat's rigid body at their position relative to the boat. I imagine each float as a cylinder which is always vertical, regardles of the orientation of the boat. The force is proportional to how deeply immersed they are, up to a maximum defined by their volume.

At the moment the boat has just 4 floats - bow, stern, port & starboard. I manually set their volumes to provide enough force to counteract gravity, and then adjust the positions and cylinder lengths to tweak the way the boat moves. I've got a vague idea to generate the floats by packing cylinders into the rigid body volume somehow, but that's something for the future

Statistics: Posted by robagar — Fri Jun 11, 2010 8:20 am

Re: Simple boat buoyancy demo

2010-06-10T09:31:31+00:00

Nice video and physic effect !

Code:

Buoyancy is modelled by attaching floats to the body which simply apply a force acording to their depth below the surface at discrete points.

Could you please explain a little further the approach you used ? From what you've written I presume you attached some rigid bodies (how many, which shape, where, with which constraint?) to the boat rigid body so that you can apply a force on each of them at every internal timestep proportional to the body distance from the water surface. Correct?

I'm not asking any source code, just a further explanation of one line or two. Thank you in advance.

Flix.

Statistics: Posted by Flix — Thu Jun 10, 2010 9:31 am