# BUG: mesh.getPositionData blows up everytime you run it

**URL:** <https://forum.babylonjs.com/t/bug-mesh-getpositiondata-blows-up-everytime-you-run-it/29246>\
**Category:** Bugs\
**Created:** [April 11, 2022, 8:42am UTC](https://forum.babylonjs.com/t/bug-mesh-getpositiondata-blows-up-everytime-you-run-it/29246 "2022-04-11T08:42:49Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![mrlooi](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/mrlooi/32/18406_2.png) [@mrlooi](https://forum.babylonjs.com/u/mrlooi)\
**Post date:** [April 11, 2022, 8:42am UTC](https://forum.babylonjs.com/t/bug-mesh-getpositiondata-blows-up-everytime-you-run-it/29246/1 "2022-04-11T08:42:49Z")

</div>

On the first time, the values are correct.

But everytime you run it afterwards, it starts blowing up based on the mesh/skeleton matrices

Here’s the PG: [https://playground.babylonjs.com/#SYQW69#1034](https://playground.babylonjs.com/#SYQW69#1034)

```auto
                var positions = mesh.getPositionData(true, true)
                console.log(positions[0]) // 58.07

                await sleep(200)
                positions = mesh.getPositionData(true, true)
                console.log(positions[0]) // 5807

                await sleep(200)
                positions = mesh.getPositionData(true, true)
                console.log(positions[0]) // 580772

```

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<div class="post-metadata">

**Author:** ![mrlooi](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/mrlooi/32/18406_2.png) [@mrlooi](https://forum.babylonjs.com/u/mrlooi)\
**Post date:** [April 11, 2022, 8:58am UTC](https://forum.babylonjs.com/t/bug-mesh-getpositiondata-blows-up-everytime-you-run-it/29246/2 "2022-04-11T08:58:22Z")

</div>

mesh.\_getPositionData seems to work correctly, is there a reason why getPositionData and \_getPositionData are different?

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<div class="post-metadata">

**Author:** ![Blake](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/blake/32/21509_2.png) [@Blake](https://forum.babylonjs.com/u/Blake)\
**Post date:** [April 11, 2022, 2:52pm UTC](https://forum.babylonjs.com/t/bug-mesh-getpositiondata-blows-up-everytime-you-run-it/29246/3 "2022-04-11T14:52:56Z")

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Here’s a PR that stabilizes the results in the PG. The new getPositionData function was missing the code to slice/copy the position array…

> <https://github.com/BabylonJS/Babylon.js/pull/12375>
>
> getPositionData needs to slice the vertex positions array after getting it from …the geometry to fix the issue in shown in below PG when getPositionData is called repeatedly and only works correctly the first time.
> 
> PG: https://playground.babylonjs.com/#SYQW69#1034
> Forum: https://forum.babylonjs.com/t/bug-mesh-getpositiondata-blows-up-everytime-you-run-it/29246