# Backedvertex animation from external source

**URL:** <https://forum.babylonjs.com/t/backedvertex-animation-from-external-source/36345>\
**Category:** Questions\
**Created:** [December 7, 2022, 12:33pm UTC](https://forum.babylonjs.com/t/backedvertex-animation-from-external-source/36345 "2022-12-07T12:33:56Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\
**Post date:** [December 8, 2022, 10:26am UTC](https://forum.babylonjs.com/t/backedvertex-animation-from-external-source/36345/4 "2022-12-08T10:26:05Z")

</div>

That’s it, except that the doc is a bit misleading, it is not vertex but bone: we store a matrix per bone, not per vertex (that would be way too much!):

```typescript
const textureSize = (boneCount + 1) * 4 * 4 * frameCount;

```

---

_[View the full topic](https://forum.babylonjs.com/t/backedvertex-animation-from-external-source/36345)._