Problem importing different Walkbehind ID's

[AndreasBlack]

I'm using AGS 3.6.1 and when i import different walkbehind Bmps's it always erases the previous one. I even Locked the ID1 and then picked another random ID where i wanted the new bmp file to go, but it just doesn't work. It get's replaced with the new import, no matter what. 
I'm guessing this is a bug, if not it would be neat to be able to do this. Since upscaling from 320x200 to 1920 x 1200 and trying to nail those walkbehinds in the AGS editor is not really an option

[Khris]

This is not a bug; importing an image replaces all existing walkbehinds because AGS assumes that the image contains all walkbehinds. You're supposed to use the first X palette slots to draw all of them, as opposed to importing them individually. (Walkbehinds cannot overlap, and are stored as a single image internally.)

The only way to keep existing ones is to temporarily replace the room background with a single-color image, take a screenshot at 100% zoom level and combine that with the new map in a paint program.

You can also open a copy of the game in AGS4; this will create a png of the walkbehinds in the game/Rooms/X folder.

[Crimson Wizard]

The only way to keep existing ones is to temporarily replace the room background with a single-color image, take a screenshot at 100% zoom level and combine that with the new map in a paint program.

There's no need to make screenshots.
You can export existing walkbehind mask to a file, there's a button on a toolbar. Then paint changes over that and import back.