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Index › Programming Questions & Help › Programs › Rain effect

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Rain effect (Read 3069 times)

Hanabi

Rain effect
Jun 8^th, 2010, 4:46am

Hi, as you will probably be able to tell I'm quite new to processing but I was hoping someone might be able to help me out. I'm trying to create a rain effect but I have so far only successfully got one drop falling :/

class Rain {
float r = random(600);
float y = 0;

void fall() {
fill(255,100);
rect(0,0,600,600);
y = y + 7;
fill(0,10,200);
ellipse(r, y, 10, 10);

}}

Rain r1;

void setup() {
size(600,600);
background(255);
smooth();
noStroke();
r1 = new Rain();
}

void draw(){
r1.fall();
}

I want to somehow have them fall many at once and at random intervals. I tried using an array to achieve this but they fell all at once and also the rectangle that I used to fade out old ellipses/create movement interferes with other drops. I do realize this is probably a very basic thing but I just can't figure it out, can anyone help me out?

PhiLho YaBB Moderator Offline Posts: 4190 Near Paris (France)	Re: Rain effect Reply #1 - Jun 8^th, 2010, 4:56am I would move the fading rectangle call to draw() instead, so you get it once per frame for all rain drops. Also you can try and create the drops in draw(), adding a new one to the array only if `random(10) < 1` for example (ie. roughly one new drop every 10 frames, adjust as you want).
	« Last Edit: Jun 8^th, 2010, 8:03am by PhiLho »

Hanabi

Re: Rain effect
Reply #2 - Jun 8^th, 2010, 6:56am

Wow thanks! That was really fast and helpful Cheesy

I now have multiple drops working together.

class Rain {
float r = random(600);
float y = 0;

void fall() {

y = y + 7;
fill(0,10,200,180);
ellipse(r, y, 10, 10);

}}

Rain r1;

int numDrops = 10;
Rain[] drops = new Rain[numDrops]; // Declare and create the array

void setup() {
size(600,600);
background(255);
smooth();
noStroke();
//Loop through array to create each object
for (int i = 0; i < drops.length; i++) {

drops[i] = new Rain(); // Create each object
r1 = new Rain();
}
}

void draw(){
fill(255,80);
rect(0,0,600,600);
//Loop through array to use objects.
for (int i = 0; i < drops.length; i++) {

drops[i].fall();

}

}

I'm still not sure though how you can use the random within draw though - it just gives me error messages. Basically what I want it to end up like is a few raindrops on screen falling at any given time, as this is eventually going to be used to make a kind of 'avoid the raindrops' game. Any more help would be greatly appreciated ;;

Cedric

Re: Rain effect
Reply #3 - Jun 8^th, 2010, 7:14am

You dont need to put random in draw.
I would keep it where it is.

So what you do right now, is create one row of raindrops but at the same height. I added another random for the height, so they enter the screen at different times.
And recall the random functions when they left the screen so they reappear at the beginning at a different position.

Code:



Rain r1;

int numDrops = 40;
Rain[] drops = new Rain[numDrops]; // Declare and create the array

void setup() {
  size(600,600);
  background(255);
  smooth();
  noStroke();
  //Loop through array to create each object
  for (int i = 0; i < drops.length; i++) {

    drops[i] = new Rain(); // Create each object
    r1 = new Rain();
  }
}

void draw(){
  fill(255,80);
  rect(0,0,600,600);
  //Loop through array to use objects.
  for (int i = 0; i < drops.length; i++) {
    drops[i].fall();
  }

}

class Rain {
  float r = random(600);
  float y = random(-height);

  void fall() {
    y = y + 7;
    fill(0,10,200,180);
    ellipse(r, y, 10, 10);

   if(y>height){
   r = random(600);
   y = random(-200);
   }

  }
}

twitter.com/CedricKiefer

Hanabi YaBB Newbies Offline Posts: 6	Re: Rain effect Reply #4 - Jun 8^th, 2010, 7:58am Ahh Thanks!! That's perfect.. makes so much sense now. I only wish I could've thought of it myself;; loll

PhiLho

Re: Rain effect
Reply #5 - Jun 8^th, 2010, 8:07am

Illustrating my idea: ([EDIT] haven't seen Cedric gave a better answer

I give it anyway...)
Code:

class Rain {
  
float r = random(600);
float y = 0;

void fall() {

 y = y + 7;
 fill(0,10,200,180);
 ellipse(r, y, 10, 10);

}

}

int numDrops = 0;
Rain[] drops = new Rain[20]; // Declare and create the array

void setup() {
 size(600, 600);
 background(255);
 smooth();
 noStroke();
 drops[0] = new Rain(); // Create first object
}

void draw() {
 if (numDrops == drops.length - 1) exit();
 fill(255, 80);
 rect(0, 0, 600, 600);
 if (random(10) < 1) {
   drops[++numDrops] = new Rain(); // Create each object
 }
 //Loop through array to use objects.
 for (int i = 0; i < numDrops; i++) {
   drops[i].fall();
 }
}

Indeed, it ends brutally, and doesn't handle when the drops go out of the screen.

« Last Edit: Jun 9^th, 2010, 1:13am by PhiLho »

Anastasios Chasandras YaBB Newbies Offline Posts: 5	Re: Rain effect Reply #6 - Jun 8^th, 2010, 3:23pm You can have a look at my code here... http://www.openprocessing.org/visuals/?visualID=9299 Hope that helps...

Hanabi YaBB Newbies Offline Posts: 6	Re: Rain effect Reply #7 - Jun 8^th, 2010, 7:40pm Ohh actually I have been looking at it, its amazing haha. Just a bit beyond my level though unfortunately. Thanks for your help guys.. saved me a lot of stressing.

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