KPF Patching for the Doom 64 Remaster

[Immorpher]

Update: Doom 64 Remaster was recently updated to fix PWAD loading, making most of the patching techniques below unnecessary. However KPF patching is still useful in adding more modability. Some discoveries are listed here: https://docs.google.com/document/d/13Yl5xBR8tZ7N6J4Pyd1ey12HxU5O5ir2pY6qilhOWt0/

When loading PWADs into the Remaster, it can crash and become unstable when custom assets (textures, sounds, and music) are used with maps. However by editing the Doom 64 IWAD you can use custom assets with your maps and mods. Then you can generate a patch from your edited Doom 64 IWAD to share your mod without distributing any copyrighted content. Applying patches is pretty common in the ROM hacking community and online tools exist to do this (so people don't need to download a patching program). Also ".bat" files can be made (thanks to phredreeke) which can install patch with just a double click for many players! More details on WAD patching, installing patches, and making patches are discussed below.

For a great example of what WAD patching offers for modability, I suggest looking at Scwiba's The UnMaking: ReMade - https://www.doomworld.com/forum/topic/125606/

Demonstration Video of Scwiba's The UnMaking - ReMade:

 

How To Install A WAD Patch

Spoiler

0) For windows users, the WAD patch might come with a .bat file which will install everything with a double click! Otherwise follow these steps.

1) Find the Doom 64 Remaster directory. For Steam, the most common location is here: C:\Program Files\Steam\steamapps\common\Doom 64\

 

2) Make a backup of the DOOM64.WAD

 

3) Use one of the websites below to upload DOOM64.WAD and apply one of the patches.

https://hack64.net/tools/patcher.php

https://www.marcrobledo.com/RomPatcher.js

 

4) Replace the DOOM64.WAD with the patched WAD, and now the mod should be running with the Doom 64 Remaster.

 

5) If Doom 64 is no longer working, replace DOOM64.WAD with your backed up version. If you have lost your backup, services like Steam can still repair the game with the "Verify Integrity of Game Files" process: https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335

Why WAD Patches?

Spoiler

Although the Doom 64 Remaster on Steam can load WADs using the "-file" command, it is very particular. It will often crash when custom assets are used when loading a WAD. However if you edit the DOOM64.WAD you can add textures, sprites, sounds, and music without crashing the game, thus allowing many more types of mods and maps to be made.

 

Unless you replace all of the assets in the DOOM64.WAD, it becomes tricky to distribute your mods without also distributing copyrighted content. However, the ROM hacking community has found a way around this. They have created programs which compare two files (called patchers) and store those differences in the patch. These differences are essentially your own modifications and do not contain copyrighted content.

 

Thus with a ROM patch you can distribute your mod worry-free. There are plenty of utilities, including websites, which allow people to easily apply your mod. You can even create a .bat file for Windows users to automatically apply the patch, which is easier than running a WAD in most cases.

 

How To Make Your Own WAD Patch

Spoiler

1) Find and make a backup of the DOOM64.WAD.

 

2) Use a text editor (like Notepad) to edit the header of DOOM64.WAD and change IWAD to PWAD. Now you can use a program like Slade (https://slade.mancubus.net/) to edit the DOOM64.WAD in any way you wish. Make sure to put levels in their on WADs within the WAD like the original DOOM64.WAD so saving and loading works properly.

 

3) Use a text editor to edit the header of DOOM64.WAD and change PWAD back to IWAD. Make sure Doom 64 runs with this newly edited WAD.

 

4) Download the Floating IPS (FLIPS) utility: https://www.romhacking.net/utilities/1040/

 

5) Open FLIPS and click on "Create Patch" and open the original DOOM64.WAD (your back up). Then open your edited DOOM64.WAD.

 

6) It will ask you to name the patch file. It will take around a minute to make sure it won't distribute any of the original DOOM64.WAD content.

7) Steam and Bethesda.net use the same DOOM64.WAD while Game Pass has a WAD which is a few bytes different due to it fixing the chaingun offset. All of these WAD types do run without issue on each other’s ports, so it doesn’t matter which one you edit initially. To cover the most people, you can make patches for both WAD types, and I have attached patches to go from one WAD version or another. But Steam and Bethesda.net will cover most people. Here are the patches: Doom64WADPatches.zip

8) Now you have your patch to distribute worry free! It's a good idea to include installation instructions from the “How to install a WAD Patch” section. You can even include FLIPS if you want. Now zip them up together.

9) Bonus! For Windows users you can create a “.bat” file to automatically use FLIPS to create and install the patch (backups and all) with a double click. It can even automatically locate where Doom 64 is for most versions and tell the difference between WAD types. Instead of building it from scratch, I recommend looking at the UnMaking: ReMade mod and organizing it the way it does, or modify it from there.

 

Special thanks to the Doom 64 Discord for discussing the concept with me: https://discord.gg/Ktxz8nz

Edited February 25, 2022 by Immorpher
Doom 64 Update changes

[UnluckySpade7]

This is really cool and I can't wait to see the potential this brings.

[Immorpher]

The promise of WAD patching has come to fruition! Scwiba's The UnMaking for the Doom 64 Remaster has been released which uses this method to load custom assets. I have updated the first post to be more descriptive with some discoveries which speed up the process. Here's a list of some of the updates.

1) Floating IPS (FLIPS) patcher is much faster when generating patches than Beat patcher. FLIPS can generate patches under a minute, which would take Beat patcher almost a half hour.

2) Game Pass has a slightly different WAD than the Steam and Bethesda.net version. Its only a few bytes different and both WADs will run in any of the Remaster releases. It seems to have fixed the chainsaw offset bug.

3) Phredreeke figured out how to bundle a .bat script with FLIPS to automatically apply patches with a double click. It looks for the Steam registry key to find the Doom 64 location, thus Doom 64 doesn't have to be in a specific directory. I expanded it to also look for the Bethesda.net and Game Pass versions as well.

Edited December 19, 2021 by Immorpher

[Immorpher]

One thing I forgot to mention! If you have installed the UnMaking, you have noticed that the title screen logo was changed, and the episode select text was updated. This was done by patching the KPF file which comes with Doom 64. This allows for an extra layer of graphics, text, and shaders to be modded.

Here's a google doc laying out what we found to be in the KPF files: https://docs.google.com/document/d/13Yl5xBR8tZ7N6J4Pyd1ey12HxU5O5ir2pY6qilhOWt0/