action triggered even on blank png pixels

i have a sprite 50x50 pixels it means 2500 pixels. but it is png file and when i click on places where are alpha channels nothing happens. is it possible to make functional whole area of sprite, even if there are alpha areas?

Under properties you can set 'Collisions' to 'Bounding box'.

it works. but i want it to be as a "tunnel" where another object can moving through it. but still it can work when i click on any part of "box"

Do you mean other objects should only collide with the actual pixels of your sprite, but you want the complete bounding box area to be clickable still?

It would probably be the easiest way to just use another invisible sprite/box object for the bounding box area.

If you meant something else please do clarify.

You can set a custom collision mask in the picture editor by clicking on the weird icon

PixelRebirth: thanks, this is what i ment

Hm, I can't do that?