Final result and some breakdowns of my entry for "The Great Transmutator" VFX contest. The rule was simple - transmute one object to another. I tried to be as procedural as I can so I utilized 3dsMax's instances and modifier stack to build sem-procedural mesh systems and then Substance Designer for all the textures. With this system you can easily swap objects, modify start/end points and adjsut the trajectory of the trails. Since the system is heavily based on lofted splines you get UVs for free, which is awesome :) Everything is assembled in Unity with some post-processing on top.
More info at the realtimevfx.com forum thread - https://realtimevfx.com/t/nikola-damjanov-tgt-competition-wip/2032
You can find all of the Substance Designer graphs and textures here - https://gum.co/phRev
Final Version
Iteration Process