Floating objects

Troubleshooting physics
1

Hi,



I have a question considering floating objects.



Goal: Have a boat floating on a water plane.



How do i get such a situation? I have one box as the water plane (static) and a cube as the "boat" (dynamic). Is it possible to get a floating effect where the cube floats on the surface instead of bouncing on it?



Another situation would be a swamp where a player gets stuck and eventually gets swallowed in the swamp.



Any ideas?



Thanks in advance!

2

Humm I don’t think the current physics system can handle dynamic fluids simulations :?



You’ll have to do it yourself (it’s a lot of maths I don’t know much) or wait for a future physics system release…

3

Too bad, i’m taking the challenge though. Expect some results soon :slight_smile:

4

Heh, i have plans for some that dont require alot of maths and stuff…perhaps we can talk about them over MSN see which ever one of our approaches is best?



DP

5

Sure thing,



I would like to set this up as good as possible from the start, i’ll contact you when you come online asap.

6

ok, so these are my thoughts on this:



Usage

Adding a FluidObject to a FluidManager and thats it basically. FluidObject is an extended StaticPhysicsObject.



Behind the Scenes

Once any object comes into contact with a FluidObject, their contact is canclled. I.e the object is allowed to penetrate the fluidObject. However, because ode is made up of a collision library and a physics library, the collision library will keep sayin those two have collided. Once they are colliding, we add a force that is proportionate to the viscousity of the liquid in the opposite direction of movement of the dynamic object. Also with that force, add a force upwards so that the object floats. This is for directional forces.



For angular forces, add a torque in the opposite direction of the current torque that has a force proportionate to the viscousity of the liquid.



Is this ok with everyone?



DP

7

The PhysicsParticleManager will be helpful in this situation.



Check the test out in CVS (PhysicsParticleManagerTest IIRC)



DP

8

Sorry for digging out an old topic  8)

Has there been any result of your discussion. I am planning a projekt involving boats and water and stumbled over the wonderful jME Screenshots and Test (ProjectedGridWater etc). Now I am wondering how to have a good physic for this water and floating objetcs in it (actually ON it would suffice).



Any hints appreciated,

thanks

Monky