Welcome to the Metruvia Content Creator Mod.io Integration Guide, the central intelligence hub for publishing Transport Fever 2 modifications outside of the PC-exclusive ecosystem. If you are a creator looking to bring your locomotives, modular stations, and script tweaks to players on the Epic Games Store, GOG, macOS, and—most importantly—PlayStation 5 and Xbox Series X|S, Mod.io is your mandatory gateway.
This pillar guide serves as the ultimate source of truth for preparing, uploading, and securing approval for your mods on the Mod.io platform. Unlike the Steam Workshop, which operates as an uncurated environment, Mod.io acts as a strict certification bridge between PC creators and console hardware. One incorrect file extension, a missing Level of Detail (LOD) mesh, or an unauthorized corporate logo will result in a swift rejection.
By mastering the technical constraints, metadata formatting, and submission workflows outlined below, you will ensure your creations pass the “Console-Ready” gauntlet on the first try.
1. The Cross-Platform Paradigm Shift
To understand the stringent upload requirements, you must first understand the architectural differences between PC and Console modding.
When a PC player downloads a massive, poorly optimized 800MB train model from the Steam Workshop, their high-end GPU might brute-force the rendering, or their game might crash. The liability is on the player. However, when Sony and Microsoft allow user-generated content (UGC) onto their closed console ecosystems, the game developer (Urban Games) assumes the liability for game stability.
Therefore, Mod.io is not just a file host; it is an automated and manual QA (Quality Assurance) checkpoint. Every mod flagged as “Console Compatible” is heavily scrutinized to ensure it does not break save games, cause memory leaks, or violate international copyright laws.
2. Technical Preparation: Structuring Your Mod Files
Before you open the Transport Fever 2 in-game publishing tool, your mod must be perfectly structured in your local directory. A sloppy folder hierarchy is the quickest path to a broken mod.
The Staging Area
Your mod must reside in the game’s local staging folder to be recognized by the publishing tool. Do not develop in the active mods folder used for downloaded content.
Windows Path: C:\Program Files (x86)\Steam\userdata\[YourSteamID]\1066780\local\staging_area\
macOS Path: ~/Library/Application Support/Steam/userdata/[YourSteamID]/1066780/local/staging_area/
The Lowercase Law
Console file systems and Linux/Mac environments are strictly case-sensitive.
Use lowercase letters for all internal files and folders (e.g., res/models/model/vehicle/train/...).
Use underscores (_) instead of spaces.
Ensure all text files (like .mdl, .mtl, and script files) are strictly encoded in UTF-8 without BOM.
Anatomy of the mod.lua File
The mod.lua is the brain of your modification. It tells Mod.io everything it needs to know about your package.
function data()
return {
info = {
minorVersion = 0,
severityAdd = “NONE”,
severityRemove = “WARNING”,
name = (“Heavy Freight Electric Locomotive”), description = (“A highly detailed fictional locomotive optimized for consoles.”),
tags = { “vehicle”, “train”, “freight” },
authors = {
{
name = “YourModioHandle”,
role = “CREATOR”,
}
}
},
}
end
The severityRemove Parameter:
This dictates what happens if a console player deletes your mod from an active save game.
NONE / WARNING: The game will safely replace missing vehicles with generic placeholders or remove the asset without crashing.
CRITICAL: Removing the mod will permanently corrupt or crash the save file (mandatory for custom industries or economy scripts). If your mod is marked CRITICAL, console players will be locked out of removing it from their saves.
3. The “Anti-Rejection” Blueprint: Console Certification Requirements
If you check the console compatible box during upload, your mod enters the Manual Review Queue. To pass, your mod must strictly adhere to the following performance limitations.
Performance and Asset Limits
Consoles utilize Unified Memory Architecture (UMA). If your mod causes a memory spike, the console OS will force-close the game.
| Metric | Limit / Requirement | Explanation |
| Max File Size | 200MB (Unpacked) | Mod.io will automatically reject anything larger. Purge uncompressed .psd files, backup files, and .DS_Store junk. |
| Textures | DDS Format with Mipmaps | Raw .tga or .png files are forbidden. You must use .dds format with mipmaps generated to prevent VRAM overflow. |
| LOD Optimization | 3 Levels Minimum | LOD 0 (Hero detail), LOD 1 (Mid-distance), LOD 2 (Far distance shoebox model). |
| Blob Files | < 1MB for lowest LOD | The .msh.blob file for your lowest detail LOD (rendered when zoomed out) must be under 1 Megabyte. |
Code and Scripting Restrictions (The Sandbox)
To prevent security vulnerabilities, Mod.io strictly enforces Lua execution limits on consoles:
Strictly No Custom Shaders: Modifying lighting or shadows is strictly forbidden.
No OS-Level Lua: Functions like os.execute or io.open targeting external directories will trigger immediate security rejections.
Absolutely No UI Alterations: Because console players use gamepads, any mod that introduces new interactable UI elements (custom buttons or menus) will be rejected due to a lack of controller nav-mesh mapping.
The “Standalone” Rule
On the Steam Workshop, creators frequently rely on dependency mods (e.g., a train skin that requires a separate 3D model mod). This is forbidden on Mod.io. All console-compatible mods must be 100% standalone and function perfectly out of the box.
4. Texture Engineering & Compression
3D meshes take up very little space; textures are the actual memory hogs. Mastering DirectDraw Surface (DDS) compression is non-negotiable.
Block Compression (BC) Formats
When exporting DDS textures from Substance Painter or Photoshop, you must choose the correct compression algorithm to balance visual fidelity with the 200MB file size limit.
Albedo (Color): Use BC1 (DXT1) for opaque textures.
Albedo with Transparency: Use BC3 (DXT5) if your vehicle has glass windows.
Metal/Gloss/AO (MGA): Use BC1 (DXT1). Ensure this is saved in Linear/RAW color space, not sRGB, or your reflections will render incorrectly.
Normal Maps: Use BC5 (ATI2) to preserve depth data without blocky artifacts.
The Mipmap Mandate: A mipmap is a sequence of progressively smaller, pre-rendered versions of your texture. If your .dds file lacks a mipmap chain, the system will automatically strip the “Console Compatible” tag to prevent texture aliasing (shimmering) at a distance.
5. The Copyright Minefield: Brands and IP
The primary reason beautifully modeled assets get rejected from Mod.io is Copyright Infringement. Sony, Microsoft, and Urban Games cannot legally distribute content that infringes on real-world corporate trademarks.
Triggers for Automated and Manual Rejections
Real-world railway logos (Union Pacific, Deutsche Bahn, BNSF).
Real-world aviation branding (Boeing, Airbus, Delta).
Trademarked product names painted on cargo assets (Coca-Cola, Maersk).
The “Look-Alike” Strategy (De-Badging)
To secure approval, you must utilize fictionalized branding or generic liveries.
Remove Explicit Logos: A train painted in the exact colors of a real-world railway will pass certification, provided the actual corporate logo and trademarked typography are absent.
Generic Metadata: Do not use trademarked names in your Mod Title. Instead of “Boeing 747-400 British Airways,” use “Heavy Jumbo Jet – Blue Ribbon Livery.”
Fictional Universes: Utilize the generic, fictional transport brands included in the vanilla game’s universe to ground your assets in the game’s lore safely.
6. The Mod.io Publishing Tool & Cloud API
Urban Games has integrated the Mod.io API directly into the Transport Fever 2 client.
The Submission Workflow
Open the Mod Browser: From the main menu, navigate to the Mod Browser. A PUBLISH tab will appear if your staging folder is formatted correctly.
Platform Selection: Change the platform dropdown from Steam Workshop to mod.io. Note that these pipelines are entirely separate; updating one does not update the other.
Metadata Check: Ensure your preview image is exactly modname_preview.jpg, has a 16:9 aspect ratio, and is under 8MB.
Publish: Add a brief changelog note and submit.
The Mod.io Cloud Dashboard
Once uploaded, manage your mod via the Mod.io web dashboard. This acts as your strategic command center:
Advanced Tagging: Apply custom taxonomies (Region, Era) so console players can filter and find your content easily.
Analytics: Track your active subscriber retention and view platform breakdowns (PC vs. PS5 vs. Xbox).
Version Control: Utilize the file history system to revert to older versions if a hotfix accidentally breaks save game compatibility.
7. Lifecycle Management & Diagnostics
Modding is an iterative process. When things break, you must know how to read the engine’s feedback.
Deciphering the stdout.txt Log
If your mod causes a crash during local testing, do not guess the cause. Open the game’s stdout.txt crash log.
“Out of Memory”: You have exceeded VRAM limits. Re-compress your textures and ensure LODs are triggering correctly.
“File Not Found”: You have a case-sensitivity error. Check your .mdl or .mtl files for capitalized texture paths.
Handling Mod.io Rejections
If your mod is denied console status, it will remain PC-only on Mod.io. Isolate the violation (e.g., an uncompressed .wav file, an oversized blob, or a stray logo), scrub the assets, increment the minorVersion in your mod.lua, and re-publish. Do not attempt to bypass the QA process, as repeated intentional violations will result in an account ban.
By adhering to this rigid structural hygiene and engineering your files for unified memory architectures, you respect both the platform and the players. A clean mod is a stable mod, and a stable mod is one that survives the transition into the cross-platform future of transport simulation.
