Number of particles

OpenGL OpenGL: Basic Coding
1

Hey guys,
I am trying to build a particle model of a breaking wave. I need to know what is a reasonable number of particles that can have positions calculated in realtime, eg between frames. Also, because the wave is breaking, i cannot use a height field to represent the ocean surface, as when it breaks, the height field will not show it properly.
Basically, I am not that interested in fancy lighting or flashy effects. I am using a 2D representation and need to find out how many particles to use.

Any ideas??

2

I think this is something you are only going to find from experimentation.

3

dunno, but heres a couple of suggestions to allow you to have some more…

Dont use dynamic data structures to store the particles (linked lists, queues etc) they will kill your frame rates.

Do store them in a nice large array.

Do look at vertex arrays to draw as much geometry as possible.

4

Err, if your going to simulate a breaking wave why not simply use a mesh?

5

Breaking waves are foamy. I have yet to see a mesh that is foamy, but a particle system could probably simulate this pretty well.

j

6

I think a mesh with particles would be good.

7

Many thanks guys,

Sorry i havent replied sooner but i have had a “FINGERS IN BLENDER” accident and have to try and type left handed.
The advice on using a data array or vertex array will be heeded. How do i use a mesh.What is a mesh? i am really very new to this game.
Also, what i am really trying to model accurately is how far the lip of the wave is thrown forward, how hollow the wave is.My eventual aim is to vary the gradient of the beach and have this affect the hollowness of the wave.
My main problem concerns how to recalculate the position of each particle between frames.
For instance, if the wave is travelling from left to right, do i calculate forces, speeds etc for particles from left to right, right to left or what.
Also how do i ensure that the movement of one particle doesnt compress the fluid. Essentially, if the particles are in a grid, do i just calculate the effect of all neighboring particles or what.

Cheers people

Ben(BlenderFool)

8

Do you fully realize what you’re getting in to? I hope that you’ve got a very string calculus background and your willing to learn fluid dynamics. If you really want to finish (or start) this program then you should start looking for programmatic approaches to fluid dynamics. It should give you all the proper transfers of energy, which you will then have to convert into kinetic energy and see how the spray goes thru the air (which even though it is not, you should treat as a non-compressible fluid)

What your proposing sounds exciting as you will be able to vary the viscosities of air and water so this program will eventually be able to simulate those oil droplets in water toys.

Wow, good luck. Program your ass off!

9

You should use a compbination of a mesh for the surface of the water and a particle engine for the foam… I can tell you this now this is a VERY hard project and requires the knowledge of fluid dynamics.