# Fisica Library removing body collision

**URL:** https://discourse.processing.org/t/fisica-library-removing-body-collision/10691
**Category:** Libraries
**Created:** [April 27, 2019, 4:10pm UTC](https://discourse.processing.org/t/fisica-library-removing-body-collision/10691 "2019-04-27T16:10:53Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![macarrony00](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/macarrony00/32/1830_2.png) [@macarrony00](https://discourse.processing.org/u/macarrony00)
#### Post date: [April 27, 2019, 4:10pm UTC](https://discourse.processing.org/t/fisica-library-removing-body-collision/10691/1 "2019-04-27T16:10:53Z")

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Hi all, I am starting a new processing project, I need some kind of world physics, for that I am using the [Fisica Library](http://www.ricardmarxer.com/fisica/). I am trying to add a specific body that do not collide with one of the others, but can’t find a way to do it, don’t even know if it is possible…

In other words: I will have 5 bodys, object 1 needs to not collide with object 2, but it needs to collide with 3, 4 and 5.

Thanks for the help, keep it up 😉

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### Author: ![jeremydouglass](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/jeremydouglass/32/20_2.png) [@jeremydouglass](https://discourse.processing.org/u/jeremydouglass)
#### Post date: [April 30, 2019, 2:05pm UTC](https://discourse.processing.org/t/fisica-library-removing-body-collision/10691/2 "2019-04-30T14:05:18Z")

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Hard to tell without more description of what you are trying to do and why, but based on the example here you could use filtering.

> <https://gamedev.stackexchange.com/questions/22540/how-to-ignore-physics-collision-of-some-objects-in-box2d/22542#22542>

Read the Fixtures chapter and the Filtering section of the Box2D manual (which Fisica is a wrapper for).

> **[manual.pdf](https://box2d.org/manual.pdf)**
>
> 1116.21 KB

In the Fisica API, that might be here (untested):

- [http://www.ricardmarxer.com/fisica/reference/fisica/FBody.html#setCategoryBits(int)](http://www.ricardmarxer.com/fisica/reference/fisica/FBody.html#setCategoryBits(int))
- [http://www.ricardmarxer.com/fisica/reference/fisica/FBody.html#setFilterBits(int)](http://www.ricardmarxer.com/fisica/reference/fisica/FBody.html#setFilterBits(int))

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### Author: ![doloresgarcia](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@doloresgarcia](https://discourse.processing.org/u/doloresgarcia)
#### Post date: [September 13, 2020, 2:10pm UTC](https://discourse.processing.org/t/fisica-library-removing-body-collision/10691/3 "2020-09-13T14:10:13Z")

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Hi, i have to do a project and i am having the same problem as you did. Did you find a way to solve it?. If you did, please let me know how.  
Thanks