We had a Photogrammetry course at Futuregames but I wanted to improve my rock so I redid it in my spare time.
I used Reality Capture to render out the mesh and then I did cleanup in Zbrush. I also did the retopo in Zbrush using polygroups with Zremesher. I then did texture cleanup in Photoshop and created the other maps from the normal and finished up in Painter.
Rendered in Marmoset.