This set of tree-shaped decorations features a selection of mathematical Triply Periodic Minimal Surfaces. The bottom can be left open for use as an electric tealight cover or decoration, or you can use the threaded insert to hold objects inside.

See here for video: https://youtu.be/5yMM924_57E

See here for stable downloads:
Gyroid: https://social.thangs.com/m/503650
Diamond: https://social.thangs.com/m/503651
Fischer Koch S: https://social.thangs.com/m/503653