# Animation blending and key interpolation bug in new CDN **URL:** \ **Category:** Bugs\ **Tags:** animationblending, animationgroups\ **Created:** [November 13, 2024, 11:19am UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729 "2024-11-13T11:19:04Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![NeuroModern](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/neuromodern/32/28683_2.png) [@NeuroModern](https://forum.babylonjs.com/u/NeuroModern)\ **Post date:** [November 13, 2024, 11:19am UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/1 "2024-11-13T11:19:04Z")
Hi, folks! After the CDN update (min and loader), i got a strange bug during the animation blending. like the mesh or parts of the mesh have a scale deformation. in the last version v6.40.0 a blending and an animation works well. in the attached video you can see the bug in the first half, and a normal behavior in the second part. how to fix it? thanks crosspost in github issues [Animation blending bug in the new CDN · Issue #15811 · BabylonJS/Babylon.js · GitHub](https://github.com/BabylonJS/Babylon.js/issues/15811) ---
**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\ **Post date:** [November 13, 2024, 4:04pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/2 "2024-11-13T16:04:30Z")
Please do not create issue on the repo. We use it to track our work Can you repro? We will need it to fix the problem Adding @Evgeni_Popov who did a lot of work on the animation code recently ---
**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:** [November 13, 2024, 5:19pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/3 "2024-11-13T17:19:51Z")
Without more details, it will be difficult to find the problem… The best solution would be to provide a repro in the playground. Alternatively, can you test different versions to see which one makes your project fail? That way, we can better target the problem. Many thanks in advance. ---
**Author:** ![NeuroModern](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/neuromodern/32/28683_2.png) [@NeuroModern](https://forum.babylonjs.com/u/NeuroModern)\ **Post date:** [November 14, 2024, 11:16am UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/4 "2024-11-14T11:16:38Z")
> **[Babylon.js Playground](https://playground.babylonjs.com/#5UIIN1%233)** > > Babylon.js playground is a live editor for Babylon.js WebGL and WebGPU 3D scenes here an example of the scale deformation. if i use let animationPhase = Math.floor(Math.random() \* 10); or let animationPhase = Math.random() \* 10; and then scene.getAnimationGroupByName(“A\_Run\_F”).goToFrame(animationPhase); i am clarify bug. animation in gltf file have not round value of keyframe position, its looks like other versions of BJS have an interpolation between keys ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/3X/f/5/f5a5cb9c0d95a887b8f7d7a699209a3c3b3564dc.png) ---
**Author:** ![NeuroModern](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/neuromodern/32/28683_2.png) [@NeuroModern](https://forum.babylonjs.com/u/NeuroModern)\ **Post date:** [November 14, 2024, 11:38am UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/5 "2024-11-14T11:38:03Z")
and also, if i skip zero keyframe i still have bug let animationPhase = Math.random() \* 10 + 1; ---
**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:** [November 14, 2024, 11:58am UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/6 "2024-11-14T11:58:28Z")
---
**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:** [November 14, 2024, 12:18pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/7 "2024-11-14T12:18:44Z")
Thanks for the repro, here’s the fix: > > > See https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-i…n-new-cdn/54729/4. > > My change in #15126 was a breaking change, because when the weight isn't -1, the animation is considered additive, and this can break if there isn't at least one animation that isn't additive. > > I needed this change for Teams Avatar, so I made a change so that the old behavior is the default, but I added a flag so that I could use the animation weight on demand. ---
**Author:** ![NeuroModern](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/neuromodern/32/28683_2.png) [@NeuroModern](https://forum.babylonjs.com/u/NeuroModern)\ **Post date:** [November 14, 2024, 12:25pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/8 "2024-11-14T12:25:24Z")
Ooo, so instant! Thanks) When it gonna be available in cdn? ---
**Author:** ![RaananW](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/raananw/32/28955_2.png) [@RaananW](https://forum.babylonjs.com/u/RaananW)\ **Post date:** [November 14, 2024, 12:58pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/9 "2024-11-14T12:58:45Z")
It was just merged, next nightly/cdn update will be available tomorrow unless @Evgeni_Popov - do you think we need to release a patch for this? ---
**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:** [November 14, 2024, 1:29pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/10 "2024-11-14T13:29:41Z")
I don’t think we’re in a hurry, unless @NeuroModern is? ---
**Author:** ![NeuroModern](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/neuromodern/32/28683_2.png) [@NeuroModern](https://forum.babylonjs.com/u/NeuroModern)\ **Post date:** [November 14, 2024, 2:22pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/11 "2024-11-14T14:22:24Z")
@RaananW @Evgeni_Popov i manually edited babylon.max.js from cdn, and compressed it by uglify-js, it is 7.2mb now instead a current cdn min version that 6mb, do not rush, it is not critical now. just tag me when it gonna be uploaded big thanks guys! have a good evening ---
**Author:** ![RaananW](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/raananw/32/28955_2.png) [@RaananW](https://forum.babylonjs.com/u/RaananW)\ **Post date:** [November 14, 2024, 2:27pm UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/12 "2024-11-14T14:27:22Z")
in aprox. 18 hours 🙂 ---
**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:** [November 15, 2024, 1:30am UTC](https://forum.babylonjs.com/t/animation-blending-and-key-interpolation-bug-in-new-cdn/54729/13 "2024-11-15T01:30:16Z")