To be fair. Simple test showed that objects are not completely blank or empty. If you disable visibility, you get 0.05% GPU with 10 or 0.5% with 1m objects. So, it's working and GPU performance increase is non-existence.
But CPU should not increase, if you got other objects which are moving. They still interact with eachother. I bet behaviors also check each other and you cannot never have blank object with it. ie: disabled/empty object which has no performance impact or link to other objects.
1 000 000, 4-8% CPU, but when some other object moves it's 80%. Which makes it ~14x increase. From this, user can have ~72 000 object, to have CPU impact 4-8% while something else moves. A mobile or laptop is much weaker and easy calculation 100k instead of 1kk, from that 100k/14 -> 7100 empty object on lower performing device with 6% CPU. Now if empty objects have behaviors or such, it will be 2-10x less objects overall. So, potentionally empty objects with behaviors ~1000 of them, which should be blank and out of reach of other object are still having major impact.
What should engine offer or have.
- Way to disable object and remove CPU impact. Like setting it invisible, which complete removes GPU impact.
- A layer where user can send objects and mark them disabled
OP post descripes empty object as parent. Which seems to be more then few sprites offscreen.
Anyway this how i see it:
Engine cannot have disabled object.
Engine internally checks other objects constantly.
Pretty sure behaviors still check eachother, even when made disabled by checkbox.
Haven't tested, but seems to be: ultimate tick mode still ticks engine math at refresh rate(60). So testing most stuff with that method, other then pure event math only, is invalid.
User cannot change internal polygon/math tick rate.
Everything has to check each other, redraw and recalc itself for next frame. User cannot influence it or change it to save perf or battery life.
Anyway. Post does not seems to be, hey use array, but shed light if empty/disabled object could be done and are blank sprites complete good, considering performance. I added in some my own ideas n stuff, because why not.