Goal

A common complaint from players is that the majority of mods are released for Resorep.  It's a powerful tool, but it's incompatible with Reshade and can be difficult to get working.  Locating textures is painful and the ID number format is tedious for both modders and users to manage.  I'm continually asked to make Forger versions of existing mods, which I wouldn't do without a direct request from the author.

My goal for writing this article is to provide another path for authors to release texture mods as forger2 files, either with or without support for Resorep.  Feel free to comment with any information you think would be helpful for other modders.

What will I need?

These are the things I expect to provide help with and answer questions about:

• Blacksmith
• Forger 2.6 or later
  

• (Very highly recommended) Experience with Resorep
• A graphics editor of your choice that works with DDS files
• A basic knowledge of DDS file and compression formats
• A good hex editor like 010 Editor.  It includes a template that breaks down the DDS file header
• Familiarity with JSON syntax or a text editor that can highlight parsing errors for you (like Visual Studio)
  

• Read the Introduction to Forger article.  The most important information for you is at the top, but you should have a basic understanding of the patch file format as well.
• Browse through the game assets with Blacksmith and familiarize yourself with the layout.  DataPC_SharedGroup_00 is the most complete and is the best forge to search for player, NPC, clothing and armor assets.
• (optional) Find your target texture filenames with Resorep if you plan to support it
• Find the target texture in Blacksmith.
  • Most of the items start with ACD_ and can be found with the Texture Map type.
  • Common abbreviations are:  CHM/CHF/CHS/CHA = character male/female/shared/animal, PLA = player, SHR = shared (usually NPC).  
  • Armor pieces usually have an ID number common to all in the set:  H01 (head), T01 (torso), W01 (waist), etc.  You can usually find the ID number using the hash id's (aka  FileIDs) from the CheatEngine Inventory list.  Simply convert them from hex to decimal, search the FileID data list, and usually the ID number is part of the asset name:  e.g.  Assassin's Belt waist 0x0000018562B759FA = FileID 1672398461434 = ACD_Waist_PLA_81_C_Hero_Of_Athen/ARMOR_SETTINGS = ACD_CHM_PLA_W81_A01_Belt_Mask1Map/TEXTURE_MAP, etc.
  • Texture names usually include DiffuseMap, NormalMap, Mask1Map, or (occasionally) Mask2Map
    
• Save the texture to a DDS file with Blacksmith and take note of the asset name and FileID (on the status bar, double-click to copy to clipboard).
• Open the DDS with a hex editor that will break down the header format for you.  In the 010 template, the mipmap data starts immediately after the last header byte.
  

• Image editor settings - Next, you'll need to verify that your image editor can save your edited texture in the same format as the original.  The game will be less forgiving than Resorep about differences.  Open your Blacksmith saved image and immediately re-save it under a new filename.  Use your hex editor to compare the first few lines of mip data (ignore the headers) between the files.  They don't need to match byte for byte, but they should be very similar if the DXT level and included channels are a match.  If they don't, change your Save settings until they do, or try different image editor.  You should also be aware of the number of mip levels your editor generates and how to change it.
• Create a test image - If you're not starting with an existing texture, you'll need to create a modified texture that will be easy to recognize in game.  Scribble across each channel of your image in places that will be visible and save a copy with 1 mipmap level.
• Determine the offset of your mipmap data - Open the test image with your hex editor and find the start of the data following the header.  It should be either at offset 0x94 (with a DX10 header) or 0x80 (without).
  

• Make up CollectionID and PatchID strings that will be unique to your mod
• Copy your DDS file into ForgerPatches and set the DataFile value (new in Forger v2.6)
• Set the DataFileOffset to the value you determined earlier.  This is where Forger will start reading.
• Your DDS file should have only a single mipmap, so Forger should be okay read to the end of the file.  If this is not the case for whatever reason, you can add a DataFileSize value to tell Forger how much to read.
  

• "Invalid escape sequence" - Backslashes in your path strings need to be doubled up: \\
• "Patch file version conflict" - You have multiple *.forger2 files in ForgerPatches that have the same CollectionID and CollectionVersion.  Increment the version number or rename unused files so they no longer match: *.forger2
• Other parsing errors - The JSON library will give detailed errors.  If you're unable to find the problem, use a text editor that highlight syntax issues for you (like Visual Studio)
  

• "Forge file not found" - Verify that file path you provided actually exists in your game folder.  It might belong to a DLC that you don't own.  The path also needs to include the .forge extension.
• "FileEntry not found in ..." - Verify that your patch file references the FileID from the data files and not the target FileID.  They are not always the same.
• "DataFile not found" - Did you forget to copy your source DDS to ForgerPatches?
• "Memory stream is not expandable" - The patch is instructing Forger to write more data than there is in the asset.  You may be writing to the wrong asset, using the wrong source file, or have mismatched content.  Verify the sizes of the source and destination mip data.  Your source DDS that you expected to have a single mipmap might have more created by your image editor.  You could still use such a file if you're not able to disable mipmap generation, but you would need to add a DataFileSize attribute to tell Forger when to stop reading (use mipmap math to find the size of each level)
  

• Make changes to the .forger2 file, then Rescan in Forger
• Make changes to the source DDS files, then install/apply in Forger
• Test in-game
• Uninstall/remove in Forger before making more changes
  

• Consult the data files to find the _TopMip_1 asset data and the corresponding copy.
• In your .forger2 file, make a copy of the target object { "File": ... } and separate them with a comma.  Edit your values to reflect _TopMip_1.
• If you're not working with an existing Resorep texture, save a copy of your mod texture that has been reduced to 50% of width and height (25% total pixels).  It doesn't need to be the final version, just something you can recognize in game.
• Save, Rescan or relaunch Forger and apply the patch.
• In the game, set the appropriate Texture Detail setting to Medium, and confirm with the camera controls (F3) that your image appears when zoomed in close.
  

• Consult the Textures data file to find its FileID (parent attribute of each TopMip).  Try the most recently modified copy first
• Create a new target object in your .forger2 and edit the values
• To create the texture, reduce your Medium texture by 50%.  This time, enable your image editor's automatic mipmap generator when saving.  You should compare the total mipmap count reported in the editor with the mipcount in the Texture data file.
• Save, Rescan or re-launch Forger and apply the patch
• In the game, set the appropriate Texture Detail setting to Low for testing