is it a sensor?

 

Here is the example of the game with both background and the button are "solid" and not sensor.

if an actor is a sensor means the actor is not solid. it can be used to replace tiles in large scenes where stencyl becomes very lag.

here are non-solid actors which means actors those let other actors through

- option panels and buttons

- game huds

- some scene decorations and lightings.

- carpets in some game scenes

So here is the collision page for an actor where it can be sensors or solid blocks 

Is a Sensor?

true = lets other actors through

false = does not let actors through