# Issue updating thin instance boundary information

**URL:** <https://forum.babylonjs.com/t/issue-updating-thin-instance-boundary-information/51901>\
**Category:** Bugs\
**Tags:** thininstances, boundingbox\
**Created:** [July 8, 2024, 9:51am UTC](https://forum.babylonjs.com/t/issue-updating-thin-instance-boundary-information/51901 "2024-07-08T09:51:11Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Akeyn](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/akeyn/32/41022_2.png) [@Akeyn](https://forum.babylonjs.com/u/Akeyn)\
**Post date:** [July 8, 2024, 9:51am UTC](https://forum.babylonjs.com/t/issue-updating-thin-instance-boundary-information/51901/1 "2024-07-08T09:51:11Z")

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Good afternoon! I recently started learning BabylonJS and I liked using ThinInstances.

So I wanted to change the position of each instance separately, I succeeded, but as soon as the instance goes beyond the bounding box the ray stops reaching the think instance.

I found **thinInstanceRefreshBoundingInfo** method that updates the thin instance’s boundary information, but it doesn’t seem to work as it should, because after executing the bounding Info is not updated.

Here is an example:

> **[Babylon.js Playground](https://playground.babylonjs.com/#RC2IAH%23136)**
>
> Babylon.js playground is a live editor for Babylon.js WebGL 3D scenes

![ezgif-4-d59ca5ae95](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/3X/6/b/6b1886d7743a135630c3f7ae7a435bd58b8076f7.gif)

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**Author:** ![roland](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/roland/32/38940_2.png) [@roland](https://forum.babylonjs.com/u/roland)\
**Post date:** [July 8, 2024, 11:06am UTC](https://forum.babylonjs.com/t/issue-updating-thin-instance-boundary-information/51901/2 "2024-07-08T11:06:35Z")

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Hello @Akeyn ! Cool avatar!

> [@Akeyn](#):
>
> because after executing the bounding Info is not updated.

Updating of the BB works. Every 4 seconds a thininstacned box is moved outside the big box and the BB is reacting respectively:

> **[Babylon.js Playground](https://playground.babylonjs.com/#RC2IAH%23140)**
>
> Babylon.js playground is a live editor for Babylon.js WebGL 3D scenes

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<div class="post-metadata">

**Author:** ![Akeyn](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/akeyn/32/41022_2.png) [@Akeyn](https://forum.babylonjs.com/u/Akeyn)\
**Post date:** [July 8, 2024, 11:40am UTC](https://forum.babylonjs.com/t/issue-updating-thin-instance-boundary-information/51901/3 "2024-07-08T11:40:53Z")

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Hi @roland!

Yay! Thank you! You saved my life!  
Now I understand the difference between a **thinInstancePartialBufferUpdate** and **thinInstanceSetMatrixAt**!

By the way, you have a cool avatar too! 😉