Hi.

There're various ways to fracture a rigid body such as rbd material fracture, voronoi, boolean etc. I think boolean fracture is prefered to others when the simulation needs to have very close camera and so more details just for one example I think boolean seems necessary. But I'm not sure with other fractures. So my question is, in what cases I need to use rbd material fracture/voronoi fracture/boolean fracture?

RBD Material Fracture is a higher-level wrapper around Voronoi and/or Boolean Fracture, depending on the material type and settings. Voronoi and Boolean Fracture are more low-level tools in comparison, and you may want to use them for building custom tools, etc or if you don't need the extra features that material fracture provides

If you just want to use specific cell points (for Voronoi) or cutting planes (for Boolean), RBD Material Fracture can be configured to use them, which allows you to have more custom fracturing while still having proxy geometry, constraints, etc still handled for you.
For custom Voronoi-style fracturing you can use the Concrete material and provide your own cell points via the fourth input, and disable the volume-based scattering
For custom boolean fracturing you can use the new Custom material type in H18, and provide your cutter geometry in the fourth input.

Thank you!