20,000 particles + bullet in real time

[slembcke]

Thought some might find this amusing. I made the following movie this weekend when working on other Chipmunk stuff. Just under 20,000 particles forming the shape of the Chipmunk logo.

http://files.slembcke.net/temp/logo_bullet.swf

For those that are wondering, it really is a real-time screen capture on my Macbook Pro. Go-go spatial hashing!

[maximile]

That's pretty amazing! When I try 20,000 circles (on a MBP) it takes 3.5s per frame, but that's without playing with any of the hash settings. Also I imagine having everything the same size helps a lot. Did you make any other clever optimisations?

[slembcke]

No, not other than setting the hash size to match the particle size. If left on the defaults, it did indeed run very very slowly. Several seconds per frame I would say.

Someday I'll get around to hierarchical spatial hashes I swear.

[ker]

Wow, that is cool!

You don't happen to object to me copying that as a logo in the loader for my game instead of the chipmunk png-logo. (By copy I mean actually use chipmunk, I want to be free of resolution bounds )
I think something like that is the perfect logo for a physics engine

[slembcke]

Sure, I don't see why not. You might need to slim it down a bit though. I was barely able to get 15fps on a fairly newish penyryn Core 2 Duo. I'll probably add it to the official list of demos soonish.

[ker]

Well... I can make it resolution dependent... ppl with low pc's won't use high res... mostly

hmm... I can't seem to find a good setting for the hash cell size, exactly the diameter of the circles(8.0) is not as good as 10.0, and higher numbers cause a loss of fps again. Higher numbers are better once the logo breaks up.

30 fps, huge hash cell number
http://www.youtube.com/v/BYupP_welAw
30-40 fps, 7000 hash cells for 6149 particles
http://www.youtube.com/v/3F5rEVGEkZU

[sickman]

Whoa! You surely got a very beefy computer!

[MatthewHudghton]

wow thats cool

[mwmerlo]

What program did you use for the screen capture? All the screen capture tools I use would have problems making that video.

[slembcke]

http://www.araelium.com/screenflick/