is there a way to pass a seperate userData to every mesh in instanced mesh?

[bhushan6]

I am rendering few models using instancedMesh but I wanna pass some unique data to every different mesh, is there way for doing it? I know about instance attribute but I want to pass through userdata

[drcmda]

instancedmesh is a single object/mesh - the instances are virtual, they are not real meshes. but if you look at these https://codesandbox.io/s/instances-h873k and https://codesandbox.io/s/instanced-vertex-colors-8fo01 you'll see that you always have data to describe each instance. you can put anything in there, positions, color, sizes, ...

const data = [...Array(count)].map((_, i) => ({
  position: ...,
  color: ...,
  text: ....,
  data: ....,
})

useFrame(() => {
  for (let i = 0; i < data.length; i++) {
    const item = data[i]
    ...
    ref.current.setInstanceAt(i, ...)

[marcelpi]

Hi,

ThreeJS keeps the transforms of all instances inside a instanceMatrix property, which is an array of transform matrices for each instance. In order to move/rotate/scale a particular instance you need to update the matrix of that instance by using .getMatrixAt(), changing it, then using .setMatrixAt().

On the same note, colors for each instance are stored in instanceColor, which is also an array having the .getColorAt() and .setColorAt() methods.

Docs: https://threejs.org/docs/index.html?q=instanced#api/en/objects/InstancedMesh

Check this example: https://codesandbox.io/s/instance-scale-gk5k8?file=/src/App.js

[bhushan6]

Thanks for replying :) That was helpful.