This scan was created using Object Capture API from Apple's RealityKit for MacOS 12 Monterey. It was generated from 47 photos took using iPhone indoor at night time. The bottom part of the seashell is captured by turning the shell upside down and I took around 15 photos underneath the shell.
The API is automatically producing USDZ file which uploaded into Sketchfab. The whole process took only a few minutes at "FULL" detail mesh quality.