Atrophy Game Engine (BIT.TRIP Series)

[Justanother]

Hello, I've got some examples of some game engine files from the proprietary game engine used to make the BIT.TRIP games, a series Wiiware games made in the early 2010's.

Almost all files contained in the attached file have file types that start with ".ae", followed up by a couple extra letters for each file type. There seem to be three notable exceptions to this.

Firstly, all sound files are stored as .OGG's, and can be opened normally. These files contain everything from sound effects, cutscene audio, and the soundtracks used in game.

Another file type that breaks the ".ae" convention are the .collision files. One of these files exist for each level, and each one varies greatly in size. Despite the odd file type, the contents can be viewed normally through a basic text editor. Each file contains a series of decimal values, each one being separated by a comma. An observation that gives insight as to what these files do is that levels 1 and 2, 3 and 4, and 5 and 6 each have similar sized .collision files (i.e, levels 1 and 2 have collision file sizes of 22KB and 18KB, whereas levels 3 and 4 have collision file sizes of 9KB and 4KB). Each pair of levels share a similar theme, and each theme has varying levels of obstacles that cannot be fired through. Levels 3 and 4 both lack obstacles for the most part, whereas the other four levels all have numerous obstacles throughout. Therefore, it's likely that these decimal values each map to the hitbox of the obstacles placed throughout the levels.

the final deviation from convention is the .vs folder under the FATE/Hell/Layouts file path. this contains various json files along with other file types that I haven't seen before (what on earth is the file at the bottom of the FATE/Hell/Layouts/.vs/Layouts/FileContentIndex?)

The remainder of these file types, as stated prior, are files made by the proprietary game engine used to make this game. Viewing and modifying these files are restricted to bitwise modifications via hex editors, and are much harder to modify without breaking things. That being said, the names of each .ae file betray their probable purposes.

.aetex files store 2D texture information. most of these files are under the "Textures2D" folder.

.aescn files store a variety of 2D and 3D objects. these files are stored throughout the whole game. These are used for the cutscenes, level backgrounds, player 2D models and animations, and all of the 3D models in the game.

.aemenu files store information about the game menus, including those that display the final score for a level, the level select menu, and the startup menu. Interestingly, the GAME OVER screen is stored as an .aescn file, and not an .aemenu file, which explains how the player isn't booted back to the menu upon defeat in game, but instead is sent back to the start of the level.

the .aeefx file type only appears one time under the Effects directory. the file "General.aeefx" doesn't have any obvious hints as to what it might contain (beyond the obvious "it contains game effects" observation).

An interesting thing to notice is that the games files are split between two directories, a "General" directory and a directory called "Hell". The BIT.TRIP series released six games on wii ware, each of them having multiple instances of shared assets throughout. the "General" directory contains those reused assets, whereas "Hell" contains the assets from this particular BIT.TRIP title.

Underneath the "General" directory is another file type labeled as .aeshader, which contains (you guessed it) shaders. Though these files are stored under the "Shaders" directory, the names attached to the .aeshader files makes it difficult to gauge what each file governs exactly.

Lastly, the fonts used for this game are stored in .aefnt files. three of these files exist, with the difference between the three being unclear.

I've attached some examples of the game engine files for those that wanna mess around with them, have fun and make friends!

AtrophyGameEngineFileTypes.zip

[shak-otay]

Nice description. (Level) mesh format appears to be simple:

Complete Level 1 seems to contain doubles (or whatever). See lower part of 2nd pic (not fully exploded).

edit: I see. Parts overlap because rotation is missing.

Edited December 11 by shak-otay