There are a lot of great surfaces to scan here in Brno. I already have a lot of point clouds to clean and process. I'll keep you posted! You can download this one for Free. I calibrate the albedos with the X-Rite Color Checker so could be a good reference for picking some colors as well.
https://www.artstation.com/marketplace/p/p8X3n/photogrammetry-stone-ground