instancedMesh onClick behavior

[RobertAron]

I have some really weird issues with instancedMesh on click. I'm pretty sure this is a r3f issue because it involves onClick. It's also a degradation - it used to work on older versions.

SANDBOX: https://codesandbox.io/p/sandbox/instanced-vertex-colors-forked-zyjxkd?file=%2Fsrc%2FApp.js%3A15%2C44

There are a few different conditions where the onClick prop stops functioning correctly.

• If the position of all of the instances is initialized at the same place
• If the meshRef.current.count is initialized at 0

In my sandbox there are a few useState(false) that have toggle buttons attached to them.

• If you run the code as is - the onClick works
• If you change either of the useState(false) to useState(true) then toggle that state using the buttons in the html, the onClick of the instancedMesh doesn't work.

Thanks so much for all your hard work <3

[RobertAron]

I had to come back around to this. It seems like the core issue has to do with the bounding sphere. It's not being updated properly. I'm not exactly sure I think maybe this should be called whenever needs update is true?

instancedMeshRef.current.instanceMatrix.needsUpdate = true;
instancedMeshRef.current.computeBoundingSphere();

The above might be slow though.

For now I'm going to fix it in my application by calling the update on an interval...but that's a pretty hacky fix. I'd appreciate a fix/insights if possible! I also wouldn't mind contributing but I think this is a pretty unfriendly first PR type problem 😓

Better sandbox. Look for the commented out code which will fix the problem by calling the compute.