Three.js

Describe the feature you'd like:

Constructive Solid Geometry (CSG) Support

Suggested implementation:

<mesh ref={boxRef}>
  <boxGeometry />
  <meshPhongMaterial />
</mesh>

<mesh ref="refSphere">
  <sphereGeometry />
  <meshPhongMaterial />
</mesh>

<union a={boxRef

I don't think this is a duplicate ticket, even though it's quite an obvious feature after that cat demo at SciPy2018.

The code that selects and renders the different geos is here in the THREE.js code
https://github.com/maartenbreddels/ipyvolume/blob/master/js/src/scatter.js#L57

I don't know quite where/how to inject the mesh definition compatible with the data file of this form, but i