Render to Mipmap Levels of Texture

Hi all,

I am trying to figure out if it is possible (using Threejs) to do the following:

I would like to create a floating-point texture (RGBA32F) with say, 10 mipmap levels. Then, I would like to render something into each level of the texture’s mipmap hierarchy. In other words, use each level as a color attachment for a WebGLRenderTarget.

The following jsfiddle shows more-or-less what I’m after in plain WebGL2 code (based on the following S.O. post). So, it would seem as though it’s possible, provided the appropriate extensions are available - I’m just not sure how to do it in Threejs.

Any help / guidance would be greatly appreciated. Thank you!