A couple of renders done using Houdini and Octane. Rendered using a single GTX 1080. The render time is relatively high but I love the look. The nebula render has very little post production. The cloud render was tweaked a little in photoshop using Color Efex pro. These are part of a new training on Volumetric Rendering.
Nebula - Render time - 1 hr 50 min at 4K resolution
Clouds - Render time - 45 min for Full HD
regards
Rohan Dalvi
http://www.rohandalvi.net/home