# How can i combine a random made background with a moving Object without redrawing?
**URL:** https://discourse.processing.org/t/how-can-i-combine-a-random-made-background-with-a-moving-object-without-redrawing/21395
**Category:** Coding Questions
**Created:** [May 29, 2020, 9:25am UTC](https://discourse.processing.org/t/how-can-i-combine-a-random-made-background-with-a-moving-object-without-redrawing/21395 "2020-05-29T09:25:45Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@JohnQED](https://discourse.processing.org/u/JohnQED)
#### Post date: [May 29, 2020, 9:25am UTC](https://discourse.processing.org/t/how-can-i-combine-a-random-made-background-with-a-moving-object-without-redrawing/21395/1 "2020-05-29T09:25:45Z")
Hello i am trying to make a starsky where i generate the background and the positions of the stars randomly.
I now want to make some fallen stars currently trying todo it with arrays.
The problem is that it always redraws it in the draw() function.
And i cant find a way to solve that problem.
Because i cant generate it in the draw function randomly because the screen woud go crazy then…
Hope you understand my question and someone can help me!
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### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [May 29, 2020, 9:30am UTC](https://discourse.processing.org/t/how-can-i-combine-a-random-made-background-with-a-moving-object-without-redrawing/21395/2 "2020-05-29T09:30:59Z")
[Processing.org/reference/createGraphics\_.html](http://Processing.org/reference/createGraphics_.html)
---
### Author:  [@JohnQED](https://discourse.processing.org/u/JohnQED)
#### Post date: [May 29, 2020, 10:29am UTC](https://discourse.processing.org/t/how-can-i-combine-a-random-made-background-with-a-moving-object-without-redrawing/21395/3 "2020-05-29T10:29:37Z")
Does not work for me, i cant call the method drawg() in the draw function and the background is also not the color i picked
```auto
PGraphics pg;
void setup() {
size(800,600);
pg = createGraphics(800,600);
}
void draw() {
pg.beginDraw();
pg.background(23, 14, 133);
pg.drawg();
pg.endDraw();
}
void drawg(){
for (int i=0; i<20;i++){
noStroke();
fill(random(17,30),random(9,19),random(125,140));
ellipse(random(0, width), random(0, height), random(40, 350), random(30, 300));
}
for (int i=0; i<250;i++){ //random Stars
float w = random(width);
float h = random(height);
fill(255);
// noFill();
ellipse(w, h, 3, 3);
}
}
```
---
### Author:  [@noel](https://discourse.processing.org/u/noel)
#### Post date: [May 29, 2020, 3:21pm UTC](https://discourse.processing.org/t/how-can-i-combine-a-random-made-background-with-a-moving-object-without-redrawing/21395/4 "2020-05-29T15:21:23Z")
> [@JohnQED](#):
>
> I now want to make some fallen stars currently trying todo it with arrays.
Using arrays is a good idea, especially a PVector array, because it can hold the x and y values.
Here is an unfinished code for you start with. You will have to change it in a way that the shooting star will fade away.
```auto
int ns = 20; // Number of stars
boolean star_fall = false;
PVector[] stars = new PVector[ns];
void setup() {
size(600, 600);
frameRate(10);
initStars();
}
void draw() {
background (0, 0, 80);
for (int i = 0; i < ns; i++) {
fill(random (50, 160));
circle(stars[i].x, stars[i].y, 5);
}
if (star_fall == true) {
PVector random_star = stars[int(random(ns))];
for (int i = 0; i < 10; i++) {
random_star.x += 10;
random_star.y += 10;
fill(255);
circle(random_star.x, random_star.y, 5);
}
star_fall = false;
initStars();
}
}
void mousePressed() {
star_fall = true;
}
void initStars() {
for (int i = 0; i < ns; i++) {
stars[i] = new PVector();
stars[i].x = int(random(10, width-10));
stars[i].y = int(random(10, height-10));
}
}
```