Hi BioXide. You’re speculation is correct. I define the body with collision shapes from primitives and meshes, attaching fragments to skeletal mesh socket/bones based on fragment-vs-shape collision. The trick is in where the fragment are spawned and traveling method: self-propelled or pull by the body shape. I call the method, Collage Construction.
I’m developing In-game Editor App to facilitate greater control and complex fragment arrangement and save/load of configurations. I’ve dubbed the editor GOLEMCraft, it will support adding/tweaking Bodypart Shapes, Fragment/Material Selection, Manual orientation/attachment of Fragments (Mesh Components), and other Components (ie: Particle Systems, Lights, Audio) to the body. The Highlight is the PaintGun Tool that will simplify applying Fragments/Fragment Clusters adjusting Fragment Scale, Dispersion Radius, and Application Patterns: Straight, Zig-Zag, Oscillation.
In the current examples to date average up to 1000 Fragments. I optimize using layers of Instanced Static Meshes and custom occlusion. I’m excited about 4.7 ISM improvements anticipating the creation of some really complex Collage Creatures constructed from 100,000’s of fragments.