Purpose of ID 0 for Walkable and Walk-Behind Areas

[Jeff Nyman]

Greetings all.

I searched the forum for an answer to this question but I can't find one and I don't see it in the manual either. I notice that when you go to set the walkable area or walk-behind area of a room, it defaults to starting you on walkbehind or walkable area with ID 1. I also notice that there is an ID 0 for both.

Does ID 0 do something special? Is it not something that should be overridden or messed with?

(Part of the reason I'm asking is I'm going to be giving a class on AGS development next year and I'm in the process of writing a tutorial for it and trying to anticipate questions I know will come up.)

Thanks for any assistance.

[Matti]

The ID 0 is for erasing other regions or hotspots. But you can do that with right-clicking the drawing tools too...

[Jeff Nyman]

matti: Thank you for the response. I am covering the aspect of using the right-click to remove areas so I think I'll just stick with that and somewhat gloss over the ID 0. I don't think it's really clear to new users on how they should use ID 0 and since it doesn't sound like they have to, there's probably little harm leaving it out.

Thanks again.

[Khris]

I'd include it, because e.g. Hotspot.GetAtScreenXY will return hotspot[0] is there's no hotspot.