Some progress. Clicking and dragging level details works, and the currently selected/highlit details will have their particle effects turned on so you can see what’s going on. Unfortunately they don’t currently update their effects when dragging — I may try making that happen, but resetting the effects is both necessary to do so and a rather expensive function call, taking almost a tenth of a second for a few thousand particles. I may want to see if I can do some optimizing there, but it’s not urgent.
Anyway, now I’m working on the slider interface element again. And, having typed that sentence, I’m now wondering if it’s a worthwhile use of my time — I started this in order to add the ability to create ‘double sliders’, sliders with two heads, for setting the minimum and maximum selectable detail range, but on a moment’s reflection I realize that it might be better just to do that with two separate sliders. Actually, with another moment’s reflection, it might also be possible to implement intuitively just using two sliders overlaid on top of each other. Dunno! Gonna sleep on it.