lol I had no idea what I was going to be able to do with that node fortunatly the SideFX video gave me enough of an idea and after a quick mess around this is how I used the node..
Video Showing my use of the topobuild node
The Main Graph

The Obj scene level

The Volumetric ( Atmospheric ) Layer

This time I incorporated Octane Render into Houdini, below shows the main materials used

Inside the rock node here, it’s real simple; I’m just using a Quixel Megascans Rock texture and box projecting it

Moon Mat

Octane Rop and Scene View

Wireframe

This is the COPS graph, after I rendered out the scene via Octane, I brought the image back into Houdini for post processing in cops. I didn’t bother with render passes so I just had the beauty render, I then did some color adjustments, added some blur to remove cg edges, added a bit of sharpen back in, vignette, chromatic aberration and some grain

So after all that, this is the final Artwork...

'Sunset on an Alien planet'