# PImage Arrays and auto scrolling photo strip
**URL:** https://discourse.processing.org/t/pimage-arrays-and-auto-scrolling-photo-strip/3074
**Category:** Coding Questions
**Created:** [August 28, 2018, 2:19pm UTC](https://discourse.processing.org/t/pimage-arrays-and-auto-scrolling-photo-strip/3074 "2018-08-28T14:19:03Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@ChrisTMChen](https://discourse.processing.org/u/ChrisTMChen)
#### Post date: [August 28, 2018, 2:19pm UTC](https://discourse.processing.org/t/pimage-arrays-and-auto-scrolling-photo-strip/3074/1 "2018-08-28T14:19:04Z")
Hi everyone!
New member to the forum here (and processing). So thank you in advance to whoever might be able to help out.
I’m working towards a bigger coding project for developing a photo projection installation, and as this is the first major project I have worked on coding in Java I am having trouble getting my head even around the basics.
Basically what I am trying to achieve is a simple photo strip that goes across a projection screen entering from the right and exiting the left (1920x1080 resolution). Pending final image size there may be 4-5 images seen on screen at once. But with a possibility of going up to 100 or more images to go through. This is why I figured an array would be best suited for this task.
In any case, the code below is pretty much based entirely off something I’ve found online [[https://forum.processing.org/two/discussion/23134/moving-images-from-an-array-across-the-screen](https://forum.processing.org/two/discussion/23134/moving-images-from-an-array-across-the-screen)], and its creating the effect I’m after. The only issue is that I am unable to turn the direction from vertical to horizontal. And when I change the length or height (which is what I thought would be the controlling variable for this. It says ‘the global variable is not set’.
Can anyone understand how the direction can be changed? or if there’s entirely a better method to approach this issue.
Thanks!
```auto
PImage[] thumbs = new PImage[6];
float x;
float y;
float thumbSpacing;
float thumbStripLength;
float thumbSpeed;
void setup() {
size(1920,1080);
for (int i = 0; i < thumbs.length; i++) {
thumbs[i] = loadImage("thumb"+i+".jpg");
}
y=0;
x=100;
thumbSpacing = height/2;
thumbStripLength = thumbSpacing*thumbs.length;
thumbSpeed = 0.5;
}
void draw() {
background(0);
x = x + thumbSpeed;
for (int i = 0; i < thumbs.length; i++) {
image(thumbs[i], y +20 , - (x + i * thumbSpacing) % thumbStripLength + height );
}
}
```
---
### Author:  [@EnhancedLoop7](https://discourse.processing.org/u/EnhancedLoop7)
#### Post date: [August 28, 2018, 4:13pm UTC](https://discourse.processing.org/t/pimage-arrays-and-auto-scrolling-photo-strip/3074/2 "2018-08-28T16:13:03Z")
So the only place I see actual movement? Would be in the line that says:
`x = x + thumbSpeed;`
Considering I have none of the pictures in your code example, forgive me for not running your sketch and actually trying out a solution? But I would say, maybe you can try:
`y = y + thumbSpeed;` ?
If not, then next I would try switching the x and y arguments inside of the image:
So I’d have:
`image(thumbs[i], - (x + i * thumbSpacing) % thumbStripLength + height, y +20 );`
Instead of what is there currently. Because I do see that you want the x-value to change, but in your current sketch, the y-value is what is changing because it has the x variable there, and hence is the part moving (if that makes sense 😃 )
Hopefully that works,
EnhancedLoop7
---
### Author:  [@ChrisTMChen](https://discourse.processing.org/u/ChrisTMChen)
#### Post date: [August 29, 2018, 3:37am UTC](https://discourse.processing.org/t/pimage-arrays-and-auto-scrolling-photo-strip/3074/3 "2018-08-29T03:37:57Z")
It worked, I understand how that works now too! Thanks so much for your help. I’m going to keep working on this.
---
### Author:  [@EnhancedLoop7](https://discourse.processing.org/u/EnhancedLoop7)
#### Post date: [August 29, 2018, 3:50pm UTC](https://discourse.processing.org/t/pimage-arrays-and-auto-scrolling-photo-strip/3074/4 "2018-08-29T15:50:27Z")
@ChrisTMChen I am glad to hear that! I wish you the best on your project 😃
EnhancedLoop7