wee doors banging

Alien Breed 3D (AB3D), published in 1995, is the fourth game in Team17‘s classic Alien Breed franchise. As the title suggests, AB3D breaks the 2D mould of the previous games; it’s a 3D first person shooter much like DOOM but with a more advanced graphics engine. It’s also one of my favourite Amiga games, if not my actual number-one-with-a-plasma-bolt favourite Amiga game, even though I was never much of a fan of the 2D games in the series.

Alien Breed 3D

In March 1997, Team17 released the source code to AB3D’s sequel, “Alien Breed 3D II: The Killing Grounds” (known as TKG), on the cover CD of Amiga Format issue 95. It was megabytes of undocumented, disorganised, messy assembly language. Andy Clitheroe, the lone programmer of both games, must have been some kind of genius, I think.

The official release was of the TKG source code. However, when poking around the CD I found the original (and equally messy) AB3D source too. Based on this code and what it revealed about the internals of the game and its data, I started four AB3D modification and remake projects. I thought I’d list them here for posterity.

Gloomy Breed

Gloomy Breed is a partial manual port of the AB3D levels to the Gloom game engine. Gloom is less capable that AB3D (think Wolfenstein 3D vs. Duke Nukem 3D)  so some compromises had to be made, but I finished six levels and they can be downloaded from girv dot net.

Alien Breed 3D RTG

I got the AB3D source code from the Amiga Format CD assembling (a major effort in itself), then started modifying it so it would be compatible with expanded Amigas fitted with graphics and sound cards, be “OS friendly” and run in the background like any application or game does on Windows today (this would have been a big deal for an Amiga game back then!). I called this project AB3D-RTG.

RTG is an acronym for “ReTargetable Graphics”, referring to the ability to redirect graphics output through any attached video hardware and not have to rely on the Amiga’s inbuilt custom chipset.

I got as far as rewriting the graphics engine so it would render through the operating system rather than “hit the hardware” directly, but it was in low resolution and wasn’t fully working. Also, I was concerned that some data and parts of functionality were missing from the source (in game keys, objects) and decided to abandon the project.

QBreed Level 1 (WinQuake)	QBreed Level 1 (glQuake)
QBreed Level 1	QBreed Level 1

Based on what I’d learned of the level data structure from the source code, I wrote a set of utilties that would convert the basic structure of AB3D levels to maps for id Software’s Quake 1 engine. Combined with a Quake mod to implement the AB3D game logic, this was QBreed.

It worked well enough for the early levels, but because the Quake 1 engine was built around 16 bit fixed point mathematics it couldn’t support the extent of map that was required to successfully convert some later ones. The floating point based Quake 3 engine supports the required map extent and I did have a version of QBreed running under Quake 3 at one point, but lacked the time to do anything more with it. This project too was abandoned, but you can download a snapshot of the final QBreed development directory here.

Alien Breed 3D - Box Art

I also created a patch, SetJoyPort, that made AB3D compatible with CD32 joypads, and a trainer. Both of these were later incorporated into and superseded by PatchAB3D by Peter Gordon but you can still download the originals from girv dot net and Aminet.

Alien Breed 3D is truly one of the stand-out classic Amiga games. Download from Dream17 and play it today!