This Geometry Nodes setup fills a target mesh with randomly distributed UV spheres. The system utilizes Raycast nodes to dynamically calculate the boundaries of the container mesh. To handle self-interaction and prevent overlap, it uses Geometry Proximity and Vector Math to adjust the position of the spheres relative to one another, simulating basic collisions without a heavy physics solver.

The node tree is built with readability in mind, serving as an accessible example for studying proximity and raycast mechanics. The provided setup is optimized for the EEVEE render engine and viewport animation, though it can be utilized with any renderer.