Realistic ball movement

Newbie & Debugging Questions
#1

How would I go about implementing realistic ball movement in my brickbreaker game? I can’t find anything on google that makes sense. Right now, the ball moves in four directions, NW,NE,SE,SW. It’s basically always moving at a 45 degree angle. I want it to move around and bounce off objects realistically. I’m not sure where to start…

#2

Something to do with the normals of the surface it bounces off.

Not sure of the formula, but I think it involves vectors & dot products.

EDIT: Just saw it is always moving at 45 degree angle.


if(collidesOnXAxisMovement())
{
    velocity.x = -velocity.x;
}
if(collidesOnYAxieMovement())
{
    velocity.y = -velocity.y;
}
#3

HeroesGraveDev’s version will work, also check this out.
I really think you should use google/your own brain a bit more, though…this is a problem easily solved just by thinking, and even if that fails you can always search.

#4

Well, you’re going to have to implement velocity, accelaration, deceleration, bounce, etc etc.

#5

I’ve already got a full system implemented. The ball moves, bounces, collides, all that. I just don’t like the way it moves. I’ve been racking my brain over this for a few days now and the only thing i’ve been able to come up with is detecting the degree of the angle before it hits a wall and compensating…I just haven’t been able to figure out how to put this into code yet.

Believe me, i’ve been searching and thinking about this. I try not to ask anything here until i’ve fully researched it…Maybe i’m just researching it wrong, but like I said, I couldn’t find what I was looking for. His solution above, doesn’t even have anything to do with what i’m asking…But thank you.

#6

Yeah, i’m working on the velocity/deceleration already. That isn’t too much of a problem. Right now, the ball moves by -1 or 1 on the X and Y axis. That’s the problem.

#7

You’re awesome. That link was what I was looking for. Thank you.

#8

An arbitrary bounce is a reflection about the normal of the surface. The parallel part is negated and the orthogonal part remains the same (assuming idealized interaction…no friction, idealized surfaces, etc).

#9

Old article I wrote:

http://petesqbsite.com/sections/express/issue21/index.html#bounce

There’s also a link there for an even older Ball to ball collision and response.

#10

I stuck a mini write-up at the bottom of this: http://www.java-gaming.org/index.php/topic,28991.msg264958.html

#11

[quote=“Bassex96,post:6,topic:41602”]
If you´ve come to the point that you want realistic movement it´s time to start learning vector math. If you used vectors you could get what is called “reflection vector” which will give you a more realistic behaviour. Here´s a link to a nice tutorial (not java code but a pretty nice description of the idea):

http://www.wildbunny.co.uk/blog/2011/04/06/physics-engines-for-dummies/

It requires that you know your way around vectors though…

#12

You guys are great. I’ve been pouring over the article Jimmt posted and it’s great but a little overwhelming. I’m going to check all of these resources out and get it implemented. I can’t wait to finish this game so I can start on something else. I’m going to change the levels to use Tiled so I can get some experience for my 2d tiled game. I think i’m going to also add some lights using box2dlights. That should be about it. It’s about finished. Everything else works great.