RMVR is an tool I developed for a production at Small Studio, Paris. The production is not out yet, but I kept working a bit on the tool, published it and rendered theses images.
RMVR sets up a raymarching environment in Unity, allowing you to play with distance functions and to display procedural shapes like fractals.
It manages camera matrices in a VR-compatible way, in order to integrate demoscene-inspired visuals into standard scenes.

The github project provides the essential informations.
Setting up the tool, and playing with the distance field presets and custom material system is straightforward using the sample scene.  Note that the flycam script is here to let you move into the scene since the render only occurs in play mode.
Integrating other shapes requires shader programming, but the tool is made to let you write them into “slots” and benefit from the material system.