# Box2D Collision Detection

**URL:** https://forum.kirupa.com/t/box2d-collision-detection/285235
**Category:** programming
**Created:** [March 29, 2009, 5:08am UTC](https://forum.kirupa.com/t/box2d-collision-detection/285235 "2009-03-29T05:08:09Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![mpelland](https://avatars.discourse-cdn.com/v4/letter/m/c0e974/32.png) [@mpelland](https://forum.kirupa.com/u/mpelland)
#### Post date: [March 29, 2009, 5:08am UTC](https://forum.kirupa.com/t/box2d-collision-detection/285235/1 "2009-03-29T05:08:09Z")

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Hey,  
I am trying to wrap my head around Box2D collision(contact) detection but i can’t seem to quite get it. I think it is half because I am really tired and have been at this thing all day.

anyways, i have a character and powerups… i am trying to allow the character to pick up the powerups. Currently the character just hits the powerup and falls down… i want to detect the collision and fire an event.

i have read up on the contactListener, but can’t seem to figure it out. please help

thanks  
marc