GTFO VR Mod Postmortem

10 points by Dsprtn 4 days ago | 4 comments

>This basically killed the mod (and other GTFO mods) for a good 6-8 months or so, until modding tools sufficiently developed to allow injection into IL2CPP Unity games.

At the time modding tools for il2cpp already existed. After looking up the timeline of events this delay can be attributed to wanting to stay on BepinEx as opposed to using another loader like MelonLoader which supported il2cpp.

>To this day, IL2CPP still means no more near-source-code access.

Since 2016 il2cppdumper exist which recovers a lot of data for the game. You get all of the classes including their fields and methods. You aren't just diving into a giant binary blind. You have a bunch of debug symbols to work off of which makes decompilers able to give you near-source-code access.

Dsprtn 5 hours ago | |

I briefly explored MelonLoader but it was also coming up short. This was quite a while ago, but if I recall correctly, the most egregious issues stemmed from the fact that I was touching deep internal parts of Unity's render pipeline. One of the last issues to be fixed was some RenderTexture-related code not being unhollowed correctly.

Halfway through 2020 the switch to Il2CPP happened and around March 2021 I was messaging with Knah, getting the aforementioned issues fixed in Unhollower before the fixes even made their way to being used in either MelonLoader or BepInEx.

il2cppdumper definitely helps a lot but the devil is in the details. Getting something specific fixed might involve understanding the interplay of many classes and methods which means having to decompile all of them, tediously.

charcircuit 4 hours ago | | |

Thanks for the reply and explanation.

>which means having to decompile all of them

This same thing applies when the game code is in C#. You may have to go through many classes to figure out how everything fits together. Decompiling all of them.