How to make a ball bounce with gravity

How to make a ball bounce with gravity

in Programming Questions • 1 year ago

Im trying to make a ball bounce when it hits the bottom of the screen. I want it to bounce as if it were a real ball, with every bounce covering less height than the one before. I've already programmed the gravity, its just the bounce which im finding difficult.

Here is the code.

int x = 200;

int y = 50;

int speed = 0;

int grav = 1 ;

//////////////////////

void setup() {

size (400,800);

smooth();

noStroke();

}

/////////////////////

void draw() {

background (0);

ellipse (x,y,30,30);

//This is where it makes gravity plus the ellpse move

y = y + speed;

speed = speed + grav;

//This is the if statement im stuck on. Regarding the bounce.

//If i leave it with speed = - speed then it bounces and comes

//down but everytime it goes higher.

if (y > 785){

speed= -speed

}

println(speed);

}

Replies(1)

allonestr..

Re: How to make a ball bounce with gravity

1 year ago

It's easy to do - you've got yourself tangled up in who does what.

All the time, the object has gravity acting on it, which causes it to fall.

Separately, you need to deal with what happens when the object hits the ground.

I've made some amendments to your code (apart from clearer variable names and punctuation):

- I've set gravity to 0.98

- I've created a new variable called vy for the velocity in the y axis. This is a good habit to get into as the obvious extension to your program is to have sideways velocity too: vx

- I've created a bounce variable - play with this to see what happens

- and I've made all the variables into floats

float xpos = 200;
float ypos = 50;
float vy = 0;
float gravity = 0.98;
float bounce = -1;
void setup()
{
size(400,800);
smooth();
noStroke();
}
void draw()
{
background(0);
ellipse(xpos, ypos, 30, 30);
// I've separated out the change in velocity and the change in position
//so that you can see what's happening
vy += gravity;
ypos += vy;
if(ypos > height - 15)
{
vy *= bounce;
}
println(vy);
}

Top Reply

Response title

Attachments

New to this Portal?