How to Change 3D Models in HOI4: Fast-Track Guide to Modding Your Game Experience

Hearts of Iron IV (HOI4) allows for a highly customized gaming experience, especially for players familiar with modding. If you want to change 3D models in HOI4—whether for units, equipment, or buildings—the process involves replacing or modifying the game’s asset files. Here’s a step-by-step guide to get you started:

1. Understand the Game’s File Structure: HOI4 stores its 3D assets in the “gfx” and “models” folders within the install directory. You’ll also interact with .txt files that define model associations.
2. Use Existing or Custom Models: Either create your own 3D models (in software like Blender) or download community-made assets compatible with HOI4. Remember, models must be in a format the game supports, such as .mesh, .anim, and use compatible textures (.dds files).
3. Creating or Editing Mods: Instead of changing vanilla files directly (which can break your game with updates), you should create a mod. Copy the relevant folders (“gfx/models”, “gfx/entities”, and “gfx/portraits” as needed) into your mod structure in the HOI4 mod directory.
4. Edit .asset Files: These files specify which model and texture files the game should use for a unit. Modify them to point to your new models. Make sure the names match exactly and paths are correct.
5. Edit .txt Files: Inside your mod, adjust relevant .txt files—usually located in “common/units” and “common/equipment”—to associate unit types with your updated 3D models.
6. Test in Game: Load HOI4 with your mod active and check that the new models appear correctly. If there are errors, review your file paths and formats.

As a designer, I recommend planning your workflow carefully, keeping model organization clean, and using descriptive file names. A tidy mod structure makes troubleshooting much easier, which is similar to maintaining organized design assets in any large-scale project. If you're aiming to build immersive environments or visualize new layouts for your HOI4 world, you might find that advanced visualization tools—like a 3D Floor Planner—can spark inspiration when planning complex alternate histories!

Tips 1:

Work incrementally and back up your original files before making changes. Preview each adjustment in-game to catch errors early. If you’re new to 3D asset creation, start by tweaking existing models rather than building new ones from scratch.

FAQ

Q: Can I use Blender models directly in HOI4?

A: No, your Blender models must be exported and converted to the formats HOI4 supports (.mesh, .anim, .dds). You may also need HOI4-specific tools or converters available on modding forums.

Q: Will changing 3D models affect my achievements or multiplayer games?

A: Modifying assets can disable achievements, and custom mods can cause compatibility issues in multiplayer. Always check mod-enabled policies before starting a multiplayer session.

Q: Where can I find HOI4-compatible 3D models?

A: The HOI4 Steam Workshop and modding communities (like forums or Discord servers) are excellent sources for ready-to-use models and modding advice.

Q: Is it possible to add entirely new unit types with custom models?

A: Yes, you can define new units and assign them unique models by editing the appropriate game files within your mod.

Q: Are there tools to make swapping 3D models easier?

A: While no official Paradox tool exists, community utilities and guides (often found on forums or YouTube) can help streamline the process of exporting, converting, and integrating 3D models in HOI4.