Hi again Michael !

Yeah I can definitely see how many users do find it useful. And that makes sense - in some cases pre-selection highlighting is quite handy, especially when things are being occluded. But as far as I am concerned I do find it to be quite a distracting visual effect because of how jittery it is : there are many different states (off, hover, selected ...), simply moving the cursor across a model makes its various components blink in and out, and so on. I suppose I would say that having the option to turn it off would be just as useful as the option to have it on :)

FP : I am not sure if this was supposed to be taken as a facetious question but I will take it as face value and will try to explain myself as clearly as possible. Preselection highlighting can be useful, but is absolutely not a necessity when it comes to selecting components in 3d space as long as the selection/component detection paradigm is reliable (and in MOI it is definitely very solid). Of course and as mentioned above there are some special cases (hidden faces) but in such cases the user can always rotate around the model, or switch to a see-through viewport style. And this can often be faster and more intuitive than hunting for a component with highlighting.

I would submit that the more comfortable one is with viewport manipulation and object selection, the less one needs visual aids like pre-selection highlighting. And if the program responds to inputs in a very predictable manner, then there is no need for visual aids/confirmation in the first place. Here is a clip showing component selections done on the components of a mesh, without any such highlighting :

https://www.youtube.com/watch?v=A-NxtQe_um4&feature=youtu.be

At this speed, having components blink in and out would be quite distracting !