# Body-specific collision callback example in Documentation

**URL:** <https://forum.babylonjs.com/t/body-specific-collision-callback-example-in-documentation/46998>\
**Category:** Questions\
**Tags:** documentation, havok\
**Created:** [January 5, 2024, 10:52pm UTC](https://forum.babylonjs.com/t/body-specific-collision-callback-example-in-documentation/46998 "2024-01-05T22:52:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![DavidP](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/davidp/32/45669_2.png) [@DavidP](https://forum.babylonjs.com/u/DavidP)\
**Post date:** [January 5, 2024, 10:52pm UTC](https://forum.babylonjs.com/t/body-specific-collision-callback-example-in-documentation/46998/1 "2024-01-05T22:52:59Z")

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Hello,  
I am trying to follow the playgrounds in documentation on collision events

> **[Collisions | Babylon.js Documentation](https://doc.babylonjs.com/features/featuresDeepDive/physics/collisionEvents)**
>
> How to access Collision Events

In the playground under “Use collision observer to log an output when bodies are colliding”

> **[Babylon.js Playground](https://playground.babylonjs.com/#7JI3E8%231)**
>
> Babylon.js playground is a live editor for Babylon.js WebGL 3D scenes

I see that bodyCollideCB (line 193) is never getting triggered even though it is registered (line 224).  
Why does that happen?  
thank you

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<div class="post-metadata">

**Author:** ![sebavan](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/sebavan/32/57_2.png) [@sebavan](https://forum.babylonjs.com/u/sebavan)\
**Post date:** [January 6, 2024, 12:34am UTC](https://forum.babylonjs.com/t/body-specific-collision-callback-example-in-documentation/46998/2 "2024-01-06T00:34:38Z")

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Adding @Cedric and @carolhmj who might be able to help

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<div class="post-metadata">

**Author:** ![carolhmj](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/carolhmj/32/25918_2.png) [@carolhmj](https://forum.babylonjs.com/u/carolhmj)\
**Post date:** [January 8, 2024, 12:51pm UTC](https://forum.babylonjs.com/t/body-specific-collision-callback-example-in-documentation/46998/3 "2024-01-08T12:51:34Z")

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`body.setCollisionCallbackEnabled` has to be set to true, see line 223: [Physics V2 collision callback | Babylon.js Playground (babylonjs.com)](https://playground.babylonjs.com/#7JI3E8#20)

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<div class="post-metadata">

**Author:** ![DavidP](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/davidp/32/45669_2.png) [@DavidP](https://forum.babylonjs.com/u/DavidP)\
**Post date:** [January 8, 2024, 5:07pm UTC](https://forum.babylonjs.com/t/body-specific-collision-callback-example-in-documentation/46998/4 "2024-01-08T17:07:50Z")

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@carolhmj Thank you! That makes sense