Modding Birthright: Gorgon's Alliance Adventures

[kasrkraw]

Goblin Apocalypse at Bindier

https://imgur.com/ZmX3D1v

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So I noticed something peculiar when I extracted the 1.4 patch which gave me a great deal of excitement: the WADS folder.

https://imgur.com/CEpo6bq

If you thought the adventures in Birthright looked Doom-y, that's because they are! The two WAD files contained in the WADS folder are map files for Bindier and Lofton using the same data structure that mods use for the original doom games. This type of cross compatibility for the data files isn't unusual as plenty of older games were built off of the doom engine. The real question was if I can access the contents of the WADs.

As far as I know there hasn't been anything developed in the birthright community for editing the adventure maps, but Doom 1 and 2 have a whole suite of community generated tools for modding these days. In particular I wanted to see the structure of a WAD from Birthright.

Using SLADE I opened the WAD for Bindier.

https://imgur.com/MdOzDsI

Looking good so far, everything is in the same format as it would be for a doom WAD. See the "Map Marker" listed as "E1M1" there? E1M1 = Episode 1 Map 1 from Doom : P, but more importantly, we should be able to load up a map from Birthright in doom. All the necessary information is there, we'll just be missing assets.

Below is Lofton from Birthright loaded into Doom

https://imgur.com/3MfRD77

And below now is a level from a Doom WAD (Alien Vendetta) in Birthright

https://imgur.com/8Pm6Pmr

It's by luck that some of the ID's for things (objects that aren't the map geometry) in the Doom WAD corresponded to enemy ID's in Birthright and vice versa. Interestingly, a lot of them were for enemies I had never seen before, like "Dwarf Officer" or "Lord", so there are certainly some near finished but unused assets lying around.

Doom X Birthright shenanigans aside, what is going to be most relevant to the community here is that there are mapping tools available for Doom that can be used for Birthright. Using Doombuilder I copy and pasted the Goblin 'thing' to create the first image of this post. Here is what that scene looked like in Doombuilder.

https://imgur.com/E92j2fK

All those question marks are there because there isn't an asset reference file available. However, the ID's and facings of things can still be edited. Map geometry should be modifiable as well, but I haven't quite confirmed that.

So what maps are editable? Presumably all of them. What is likely happening is that the WAD's contained in the WADS folder are PWADs and override the core data files for the maps, so replacing another map would involve creating and inserting a WAD into the WADS folder with the same name as it. This is gist of what I did to insert a Doom WAD into birthright (renaming to BINDI_MW.wad and making sure the markers were set up correctly).

Without necessarily knowing what ID corresponds to what asset it seems entirely possible to manually increment through all possible ID's to determine what ID corresponds to what textures, what objects, etc. to allow creation of maps for Birthright: Gorgons Alliance. For the time being I'll keep exploring what the bounds of editing are in this manner, and maybe at some later date get back to the community with more technical information on this topic as well as use notes for the doom tools.