Learning Soft Body

Hi there,

A good place to start is to make a loop of particles connected with springs. Then calculate the rest-area (or "2d volume") using the equation found here, and save it.

For each program loop, calculate the current area and calculate a pressure force, which could look like this:

Fpressure = stiffnes * (area - rest area)

Which is essentially just Hooke's law of elasticity in another form. Then, for each spring, apply a perpendicular pressure force to the particles in each end of the spring.

Integrate with time using your favourite algorithm and repeat. This will make the loop of springs into a neat little water balloon :-)

Cheers,
Mike

Thanks, but I don't really know how to do springs. Is there a good tutorial for this stuff?

Ah, okay. Let's go the other way around, then. To succeed with this you first need to know a few things about vector math, and I recommend you to write your own vector library containing all the stuff you need. In my opinion this is a brilliant way to learn math. You'll need to know how to find the length (or magnitude) of a vector, and you need to know what a normalized vector is. Also, you'll need to know how to find the perpendicular of a vector and how to find the dop product or scalar product of two vectors. Filally, you need to know how to project one vector onto another. There are loads of vector primers and beginner's tutorials out there, and I recommend you read through a few of them.

Cheers,
Mike

There is a realtime physics course from Siggraph, which I found to be introductory, practical and comprehensive, you can start from there.
Among soft bodies, spring systems and finite elements systems are covered.
link: http://www.matthiasmueller.info/realtimephysics/index.html

So, are you having any progress on implementing soft body physics? It'd be really nice of you to drop a note on wether you've had all the help you needed.