Diagonal GUID Mystery

Recently, two other modders, on discussion groups I frequent, have had issues with objects being undeletable unless they were placed on the floor. Couldn't be deleted if they were placed on counters, tables, end tables, etc, nor by picking them up and clicking on the UI panel. More of an annoyance than a show-stopper.

We'd assumed that it was something to do with the object's flags when initialised, or guardians/actions in the OBJf. Turns out it's something much, much stranger.

Having eliminated those possibilities by taking one of the objects and paring it right back such that is was a static deco object and comparing it to a standard game deco object, the only differences were in values in the OBJD resource itself - Default Wall Adjacent Flags, Default Placement Flags, etc. Eliminating those one by one, the culprit turned out to be the "Diagonal GUID" value!

Now, the Diagonal GUID value is one half of the magic that connects straight and diagonal doors, windows, arches, etc - see this tutorial for more details.

BUT, it also has a hidden side-effect on other objects! Set this value to 0x00000000 and you can't delete the object unless it's on the ground. Set it back to 0x00010000 and you can delete the object from any surface and via the UI panel.

Hope these notes are of use to someone. Enjoy!

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