Advanced overlapping detection ?

[donmanolo]

Hi there !
I've been looking for a way to do that for quite a long time, but so far I didn't find anything. For my project, I need to detect whether two object are completely overlapping or not. (for example Object 1 is completely hidden by Object 2)

Do you know if there is a way to do that ?

[LB]

Yes: you have a thin object as the outline for the bigger object and if the smaller object is overlapping the bigger but not the outline then it is a full overlap. It works if they are the same size, too, but in any case the outline needs to never overlap with its object.

[donmanolo]

Well, this could work with for rectangular object. What is rather problematic is that my objects are very randomly shaped. But anyway thank you for the advice

[LB]

The shape does not matter, and the outline doesn't even have to be thin - it can be as simple as inverting the transparency if your object.

[donmanolo]

Well I know that the shapes isn't a problem to have your solution working. (anyway ,any object in MMF2 is rectangular whatever it may look) But what the player sees does matter and your solution might trigger events when it is not necessary.

[BrashMonkey]

if theres transparent bits inside, like a window, you would need to reflect that too in the "outline"..

the obvious downside is for every object, you need an outline object , so if theres lots, you're gonna hit the frame rate hard.

[donmanolo]

Indeed, that could work. If I create an outline object, I can test if my active is overlapping the object itself and is not overlapping the outline object. If that's true ,that means my object is hidden.

By the way, do you know if there is a way to test whether or not an object is overlapping an object that is on another layer ?

[nivram]

If the object to be overlapped is stationary, can you not use its x,y position with the x,y of the overlapper?

Marv

[LB]

Indeed, that could work. If I create an outline object, I can test if my active is overlapping the object itself and is not overlapping the outline object. If that's true ,that means my object is hidden.

THis is exactly what I was suggesting...also, it may be helpful to note that invisible objects can still collide, even with visible objects.