# MergeMeshes cannot merge imported meshes and MeshBuilder meshes (Mesh)

**URL:** <https://forum.babylonjs.com/t/mergemeshes-cannot-merge-imported-meshes-and-meshbuilder-meshes-mesh/37503>\
**Category:** Bugs\
**Tags:** mesh\
**Created:** [January 18, 2023, 9:09pm UTC](https://forum.babylonjs.com/t/mergemeshes-cannot-merge-imported-meshes-and-meshbuilder-meshes-mesh/37503 "2023-01-18T21:09:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Nawar](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/nawar/32/14923_2.png) [@Nawar](https://forum.babylonjs.com/u/Nawar)\
**Post date:** [January 18, 2023, 9:09pm UTC](https://forum.babylonjs.com/t/mergemeshes-cannot-merge-imported-meshes-and-meshbuilder-meshes-mesh/37503/1 "2023-01-18T21:09:59Z")

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Hello!

In this example, there is an imported mesh (consisting of 7 meshes) and two meshes created by `MeshBuilder`.

If you try to `MergeMeshes` all 9 meshes, `null` will be returned. This is not correct behavior.

> **[Babylon.js Playground](https://playground.babylonjs.com/#8PFMR5)**
>
> Babylon.js playground is a live editor for Babylon.js WebGL 3D scenes

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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 18, 2023, 11:37pm UTC](https://forum.babylonjs.com/t/mergemeshes-cannot-merge-imported-meshes-and-meshbuilder-meshes-mesh/37503/2 "2023-01-18T23:37:26Z")

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This is not a bug but a limitation of the process.

You can actually see in the console log:

 ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/3X/7/b/7b887eaaf2c5820c90374a16eff54f67299fa4be.png)

Basically the face orientation being different are preventing the process to be possible.

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<div class="post-metadata">

**Author:** ![Nawar](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/nawar/32/14923_2.png) [@Nawar](https://forum.babylonjs.com/u/Nawar)\
**Post date:** [January 19, 2023, 12:54am UTC](https://forum.babylonjs.com/t/mergemeshes-cannot-merge-imported-meshes-and-meshbuilder-meshes-mesh/37503/3 "2023-01-19T00:54:41Z")

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Understood. Thanks, I missed that

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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 19, 2023, 1:08am UTC](https://forum.babylonjs.com/t/mergemeshes-cannot-merge-imported-meshes-and-meshbuilder-meshes-mesh/37503/4 "2023-01-19T01:08:02Z")

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no problem, it is not always the most obvious. you could try in right handed mode as in this case I belive both loaded gltf and created elements will have the same handedness.