# Random motion with irregular shape
**URL:** https://forum.kirupa.com/t/random-motion-with-irregular-shape/12392
**Category:** Uncategorized
**Created:** [January 30, 2003, 6:28pm UTC](https://forum.kirupa.com/t/random-motion-with-irregular-shape/12392 "2003-01-30T18:28:13Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@daveg92656](https://forum.kirupa.com/u/daveg92656)
#### Post date: [January 30, 2003, 6:28pm UTC](https://forum.kirupa.com/t/random-motion-with-irregular-shape/12392/1 "2003-01-30T18:28:13Z")
Hello,
I’m using Flash5 and was wondering if anyone knows how to create random motion of an object within an irregular shape?
I have an ob-long rectangle which ‘flares’ on each end and would like to place some graphics in random motion within this irregular shape. Kirupa has a nice tutorial on random motion, which I can follow and re-produce no problem. However, with his tut, he uses
movie\_height = 150;
movie\_width = 300;
But I want to specify the top, bottom, left and right edges, which are irregular. Should I create a mask and use that? or can I achieve this another way using actionscript? thanks for your help!! dave.
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [January 30, 2003, 6:41pm UTC](https://forum.kirupa.com/t/random-motion-with-irregular-shape/12392/2 "2003-01-30T18:41:51Z")
You will need a mask.
The only thing Flash can change is the width/height and \_xscale/\_yscale.
---
### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [January 30, 2003, 6:47pm UTC](https://forum.kirupa.com/t/random-motion-with-irregular-shape/12392/3 "2003-01-30T18:47:39Z")
cool, thanks. i thought that might be the case, but not sure.