I cannot find ANY information regarding water physics and/or boat physics. I''m in the process of writing a game solely based upon players in the water on jet skis and boats. So far its well, but there''s absolutely no physics... If anyone can think of anything that might be useful (dont get me wrong, I''ve spent many nights thinking about it), or know of any tutorials or articles, please let me know! Thanks for the help, ~Dwarf

You might want to look up "physics" + "buoyancy" or "hydroplaning". There may be some resources at www.aerohydro.com. They are a company that produces software that is heavily used for boat design. Don''t know of any real suggestions for water ski/jet ski physics, though.

Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.

Well I''m not looking for those types specifically, just in general.

I was thinking that if you assign each object its own

pos[3], vec[3], and mass,

you could determine its speed by using some calculations based on the time accelerated, the water resistance, mass, etc.

It''s like using car racing physics, with a whole lot less traction, right?

~Dwarf

The resistance will be dependent on how deep you are in the water, as the air friction is much less than the fricion inside water.
That again will be dependent on how fast you are, so i see a kind of the faster, the less friction you have.
you will need to calculate the speed of your jetski, then check your ski-normal, calculate the resulting force lifting your jetski....

A lot of math if you want to do it correct.

I think I would use a modified version of the systems used for car races...
medium friction is dependant from the squared speed, also from the medium.
As you lift more out of the water with higher speed, so your medium will go from fully inside water over half-half to almost only air at highest speed...

only some thoughts on that, hope this helps you some.

Well, using the cheap hacks that I do, I would just treat it like really slippery ground that allows intersections.

Moe''s site

There''s an article on it in Game Programming Gems I. It goes over simulating waves & coastlines for bodies of water, and how to make realistically buoyant objects. Comes with source code/demo program on CD.

Also, see the GDCE article at www.swrendering.com/water.html . The paper is at the bottom of the papers page, but there are screenshots and avi movies on the linked page.

Drag also depends on whether the flow of water over the hull is laminar or turbulent.
“Physics for Game Developers”* has a chapter dedicated to ships, builds on the material from projectiles & aircraft. What’s funny, is the material in that book is rather simplistic – but the examples are far more involved than anything you’ll cover in standard college physics. When I asked my ME (mechanical engineering) buddies about 3D kinematics equations, they gave me a blank look and said statics & dynamics only covered 2D!


*by David M. Bourg – at 40 bucks it’s a good deal.