Vertex Animation breaks reflections

Questions
1

Hi everyone,
I’m having some troubles with reflections together with vertex animations.

What I’m trying to achieve is a piece of cloth vertex animated to showcase some particular fabrics. The problem is that the reflections that comes from the surrounding HDR are not correctly updated.

As an example I created a sphere with metalness 1 and roughness 0. This sphere has a vertex animation that makes it rotate.
Here the link to the model: https://metaverso.it/demo/static/balla2.glb

If you open this model with donmccurdy’s viewer ( https://gltf-viewer.donmccurdy.com/ ) you will see the HDR reflected on the sphere rotate with the sphere. If the reflections were correct you should see nothing at all, the rotation should be totally unnoticable.

Before opening a new topic the only related one I found is this: Reflection looks weird after updating geometry vertices
but I didn’t manage to fix my problem.

Any insight?

Thanks!

2

Just to note – this is a “morph target” (also called “shape key”) animation, as opposed to other types of vertex animation. I’m not sure why rotation affects the reflections, but the same thing appears in https://sandbox.babylonjs.com/ … I’m a bit surprised by that, it would be fair to file an issue I think.

3

Hi don,
Issue filed: Morph Target Animations break Reflections · Issue #24201 · mrdoob/three.js · GitHub

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