Although I've retreated from a lot of of my art, following the loss of my computer and becoming disabled (not in that order), I eventually replaced the computer with a new laptop. I was not able to recover any of my 3D projects, but I still owned copies of Filter Forge and World Machine, so that's where I focused my creativity. Someday, I'll get back into 3D, but right now my computer is barely capable of doing it.
This project is the first I've been motivated to share, though it's far from my first Filter Forge filter. You can find others in the FF Library, free to download if you have Filter Forge. In the middle of making another filter, I discovered I had put together a good foundation for a cliff face. Taking a break from that project, I put this together while it was still on my mind. This creates a mossy or lichen covered rock face with fine flecks of metallicity, wetness and a complete PBR materials set. I recommend the non-seamless mode, the rock looks a bit more natural that way. These samples are all at the default 600x600 px which I saved while finalizing the filter. They are the requisite nine presets needed to submit the filter to the library, so you can download the filter and render them at higher resolution if you're a FF user. The complete PBR materials are shown for the first preset, with the rendered versions of the remaining eight.
Edit: I was able to create an optimized mesh for Preset 001 using World Machine. The version on Sketchfab is fairly low resolution, but so were the materials rendered for it. I may make a higher res version available for download at some later time.