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 John_Clark 01-25-2008 11:18 AM

spherical collision & rebound angles

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Hey I'm doing a pool game, as you may have seen from my other thread, but I have run into some issues. One is that I need help with spherical collision & rebound angles. Number two although is a bigger issue, I'm only a Jr in High School and I don't know alot about physics and next to nothing about Trig so I really need help with both of those although I need more help with rebound angles, so anyone have any idea/equasions that could help out?

P.S. I've added the pool game on here as well if people want to take alook although I haven't done a huge amount to it yet.

 DickBaldwin 01-25-2008 01:15 PM

Here is a link to some information on collision detection in 2D. This approach should work well for pool balls if you extend it to 3D, [I](which is not necessarily a trivial task for someone with a weak math background).[/I]

[URL="http://www.jumbooks.com/books/Computers%20and%20Internet/wordware%20java%201%204%20game%20programming/source/5785final/lib0136.html"]http://www.jumbooks.com/books/Computers%20and%20Internet/wordware%20java%201%204%20game%20programming/source/5785final/lib0136.html[/URL]

However, this won't help you with the rebound issues. To be frank, it sounds to me like you may have taken on a project that is beyond your current educational level. A computer program that simulates a pool game is simply a model of something that happens in the real world. If you are unable to create and understand a mathematical model of what happens in the real world, it is unlikely that you will be able to write a computer program to model it. Just in case you haven't found it on the web, here is a link to an article about the math of a billiards game:

[URL]http://archive.ncsa.uiuc.edu/Classes/MATH198/townsend/math.html[/URL]

But, don't give up. You may be able to learn enough on the fly to make it all work.

[I]PS: Under the stipulation that the pool balls must remain on the table, you can consider this to be a problem of circles moving in a 2D space instead of spheres moving in a 3D space. This will make the task much easier than would be the case if it were spheres moving in a 3D space, but still fairly difficult.[/I]

Dick Baldwin
Free Alice tutorials: [URL]http://www.dickbaldwin.com/tocalice.htm[/URL]
Free programming tutorials: [URL]http://www.dickbaldwin.com/toc.htm[/URL]

 DickBaldwin 01-26-2008 09:14 PM

See [SIZE=-1]algorithmancy.8kindsoffun.com/HStrig.ppt It deals with hockey puck collisions and you may find it helpful.

Dick Baldwin
Free Alice tutorials: [url]http://www.dickbaldwin.com/tocalice.htm[/url]
Free programming tutorials: [url]http://www.dickbaldwin.com/toc.htm[/url]
[/SIZE]

 John_Clark 01-28-2008 11:15 AM

Ok thanks, and luckily I do know some people that can help as well as a kid whos may end up going to MIT so I should be able to do this, and it helps that I'm a fast learner.

 DickBaldwin 01-29-2008 10:37 PM

[quote=John_Clark;4514]Ok thanks, and luckily I do know some people that can help as well as a kid whos may end up going to MIT so I should be able to do this, and it helps that I'm a fast learner.[/quote]

Fantastic. I hope you succeed.

Dick Baldwin
Free Alice tutorials: [URL]http://www.dickbaldwin.com/tocalice.htm[/URL]
Free programming tutorials: [URL]http://www.dickbaldwin.com/toc.htm[/URL]

 John_Clark 02-05-2008 11:16 AM

Ok, I think I have the general idea on how to do everything I need to but now I'm just wondering how I should set up the equasion and if I should set it up in some if else statements imbeaded in each other or to use if else statements in some kind of loop

 DickBaldwin 02-05-2008 11:54 AM

[quote=John_Clark;4558]Ok, I think I have the general idea on how to do everything I need to but now I'm just wondering how I should set up the equasion and if I should set it up in some if else statements imbeaded in each other or to use if else statements in some kind of loop[/quote]

It sounds like you should probably start at the beginning and learn a little more about programming fundamentals and program design on a few somewhat simpler projects.

Dick Baldwin
Free Alice tutorials: [url]http://www.dickbaldwin.com/tocalice.htm[/url]
Free programming tutorials: [url]http://www.dickbaldwin.com/toc.htm[/url]

 John_Clark 02-07-2008 11:16 AM

Ya, I think I'm going to just put this one on hold for a while and work on some smaller ones until I get a bit better backround in math and physics. But for my other thing I said [QUOTE]Ok, I think I have the general idea on how to do everything I need to but now I'm just wondering how I should set up the equasion and if I should set it up in some if else statements imbeaded in each other or to use if else statements in some kind of loop[/QUOTE]
I just wanted to get some other opinions on what would be more practical.

 DrJim 02-07-2008 11:34 AM

Pong?

A "pong" type game might be a good start - it would give you the basics of ball movement and rebounds. You could then gradually substitute a pool cue for the "paddle" and eventually move up to more complete physics.

I believe the Scratch forum has several examples to give you some ideas for a start.

 John_Clark 02-08-2008 11:33 AM

Ok, thanks Jim.

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