3D models for the background figures (used as particle point clouds).
CC-BY attribution is required. Originals were optimized (geometry
simplification + quantization, materials/textures stripped).

brain.glb — "3D Labeled Brain Model"
  by ashlynnsnead (https://sketchfab.com/ashlynnsnead)
  https://sketchfab.com/3d-models/3d-labeled-brain-model-5fd423f044754539b9e8eada7b80f52a
  CC-BY-4.0 (http://creativecommons.org/licenses/by/4.0/)

bulb.glb — "Light Bulb"
  by p3arl (https://sketchfab.com/p3arl)
  https://sketchfab.com/3d-models/light-bulb-553f292157bf40f99dfb20979bf14d5f
  CC-BY-4.0 (http://creativecommons.org/licenses/by/4.0/)

comet.glb — "Asteroid"
  by kayra23 (https://sketchfab.com/kayra23)
  https://sketchfab.com/3d-models/asteroid-d3b95b50c02a482d927f224b623bb83d
  CC-BY-SA-4.0 (http://creativecommons.org/licenses/by-sa/4.0/)
  (ShareAlike: this is a modified version, released under the same license)

humpback_whale.glb — "Game-ready Humpback Whale"
  by Allie2k (https://sketchfab.com/Allie2k)
  https://sketchfab.com/3d-models/game-ready-humpback-whale-da07e3ff73914ff28d2b8cf9da794036
  CC-BY-4.0 (http://creativecommons.org/licenses/by/4.0/)

question_mark.glb — "question mark"
  by UL (https://sketchfab.com/unmanned.lifemail)
  https://sketchfab.com/3d-models/question-mark-e0969716da6c4168a1d98067be48769a
  CC-BY-4.0 (http://creativecommons.org/licenses/by/4.0/)

gift.glb — "Gift box"
  by Kyn (https://sketchfab.com/Kyn91)
  https://sketchfab.com/3d-models/gift-box-95719378a4dd49cebe0fbb45713b33f0
  CC-BY-4.0 (http://creativecommons.org/licenses/by/4.0/)