But that’s what I’m saying, you shouldn’t care that much, it’s transparent to you.
Do you care whether a rendering engine uses RGrids, OCTrees, BTrees, BVH, or something else for its scene data? Unless the system is badly implemented, and therefore you need a knowledge of it to just get it to work (See MRay’s horrible BSPs for years), it’s the kind of stuff you don’t want to care about unless you’re on the technical end of things, because you have no control over it. It’s how something is done, that’s it.
Does an engine use SH to condense, or simplify, or defer/refer recomputation when you move the camera? Or do they have some very smart way of aligning and accessing data propietary to that engine? Or do they do something else again such as using the GPU to brute force the lot?
Do you care as long as recomputation as soon as you move the camera is instantaneous?
As I said, SH isn’t some magic trick, or a mystery. It’s one of many means to an end that can be used in different places, to different extents.
It should be transparent to you as a user, and therefore time’s better spent elsewhere.
Unless you have a genuine interest in the technology and the fundamentals, in which case you SHOULD read about the mathematical and CS sides of it, then it’s irrelevant whether an engine uses it or not.
Like many things for a while it was hyped, and SH found its way to the lips of many who don’t really know or care for it, much like radiosity did at some point. It doesn’t deserve stardom status, it’s just one of many options. Study it from the basics if you want to understand it, or leave it alone IMO.
There’s hardly anything you can do about it even if you understand it anyway, if you feel like studying your time is much better spent understanding some basics of the sampling models and rules to optimize your renders, not how a particular calculation is condensed in such a way you can affect no change in it whatsoever.