This relates on vertices of a mesh in unity.
Particles (here spheres) are spread in the scene, exploring the world will reveal the hidden meshes.
While getting close to a mesh, the particles will start moving to the vertices of the mesh, reconstructing it.
When getting further from it, the particles will detach in an explosion.
This work is appliable on any mesh, with any kind of particles.
My part of the project was to do a rework on the mesh to obtain a new mesh
with an homogeneous appearance even with a low number of vertices initially.