Yes that's true, but what if you could use only simple rectangular polygons? Wouldn't they act as a simple one colour fill detector sprites?
I'm asking because i have many layouts with single sprite's for a background and I have to set few custom sprite detectors for a specific layout - there's some Z layering and other thing to consider.
If for one layout i have to set let say 5 of them - and I've already have 9 layout, it equals 45 objects for detectors only :/
I though if I could have multiple collision masks and they could be called in events by name I could save time and export file size.