Introduction to Modding Doom Eternal

As a seasoned modder, I've spent countless hours tinkering with various games, but there's something special about creating mods for Doom Eternal. The game's intense, fast-paced gameplay and iconic weaponry provide a perfect canvas for creativity. In this guide, I'll walk you through the process of creating a custom weapon mod for Doom Eternal, specifically focusing on enhancing the BFG-9000.

Before we dive in, it's important to note that modding Doom Eternal requires patience, attention to detail, and a basic understanding of 3D modeling and programming. Don't worry if you're new to this; we'll break down each step to make it as accessible as possible.

Tools and Prerequisites

To get started, you'll need the following tools:

• Doom Eternal (obviously)
• Blender (for 3D modeling)
• GIMP or Photoshop (for texture editing)
• Visual Studio Code (for script editing)
• IdTech 7 SDK (Software Development Kit for Doom Eternal)
• Doom Mod Tools (available on the Bethesda.net launcher)

Make sure you have all these installed before proceeding. The IdTech 7 SDK can be a bit tricky to find, but there are community resources available that can help you locate it.

Conceptualizing Your Custom Weapon

For this tutorial, we'll be creating a modified version of the BFG-9000, which we'll call the "BFG-X". Our version will have additional energy cores and a secondary firing mode that releases a swarm of smaller energy projectiles.

When conceptualizing your weapon, consider the following:

• Visual design: How will it differ from the original?
• Functionality: What new features will it have?
• Balance: How will it fit into the game without being overpowered?

Sketch out your ideas or create a mood board to guide your design process.

3D Modeling in Blender

Now, let's get our hands dirty with some 3D modeling. Open Blender and import the original BFG-9000 model (you can extract this from the game files using the Doom Mod Tools).

Here's a step-by-step process to modify the model:

1. Duplicate the main body of the BFG-9000.
2. Add two additional energy cores on either side of the main barrel.
3. Extend the barrel slightly and add vents for the secondary firing mode.
4. Adjust the grip to accommodate the new features.

Here's a snippet of Python code you might use in Blender to automate part of this process:

import bpy

def add_energy_core(x, y, z):
    bpy.ops.mesh.primitive_uv_sphere_add(radius=0.5, location=(x, y, z))
    core = bpy.context.active_object
    core.name = "EnergyCore"
    
    # Add emission material
    mat = bpy.data.materials.new(name="CoreMaterial")
    mat.use_nodes = True
    nodes = mat.node_tree.nodes
    emission = nodes.new(type='ShaderNodeEmission')
    emission.inputs[0].default_value = (0, 1, 0, 1)  # Green color
    emission.inputs[1].default_value = 5.0  # Strength
    mat.node_tree.links.new(emission.outputs[0], nodes['Material Output'].inputs[0])
    
    core.data.materials.append(mat)

# Add two energy cores
add_energy_core(1, 0, 0)
add_energy_core(-1, 0, 0)

Remember to adjust the coordinates and scale to fit your specific model.

Texturing Your Custom Weapon

With the 3D model complete, it's time to texture our BFG-X. Export your model's UV map from Blender and open it in GIMP or Photoshop.

Here's a quick guide to texturing:

1. Use the original BFG-9000 texture as a base.
2. Add glowing effects for the new energy cores.
3. Create a unique pattern for the extended barrel.
4. Add wear and tear for a realistic look.

Pro tip: Use layer masks and adjustment layers to easily modify your texture without destroying the original work.

Implementing the Mod in Doom Eternal

Now comes the exciting part - bringing your creation to life in the game! This process involves several steps:

1. Export your 3D model from Blender in a format compatible with the IdTech 7 engine (usually .md6).
2. Use the Doom Mod Tools to import your model and textures into the game's file structure.
3. Create a new weapon definition file for the BFG-X.
4. Modify the game scripts to include your new weapon.

Here's an example of what your weapon definition file might look like:

{
    "weaponName": "BFG-X",
    "modelPath": "models/weapons/bfg_x/bfg_x.md6",
    "texturePath": "textures/weapons/bfg_x/bfg_x_d.tga",
    "fireRate": 80,
    "damage": 100,
    "ammoType": "cells",
    "ammoPerShot": 30,
    "secondaryFire": {
        "type": "energySwarm",
        "projectileCount": 10,
        "spread": 15,
        "damage": 20
    }
}

Scripting New Functionality

To implement the secondary firing mode, we need to write some custom scripts. In Visual Studio Code, create a new script file called "bfg_x_logic.script". Here's a simplified version of what this script might contain:

class BFG_X extends Weapon {
    function FireSecondary() {
        for (int i = 0; i < 10; i++) {
            Vector3 direction = CalculateSpreadDirection(15);
            SpawnProjectile("energy_bolt", this.position, direction);
        }
    }
    
    function CalculateSpreadDirection(float spreadAngle) {
        // Implementation of spread calculation
        // ...
    }
}

This script defines the secondary fire function, which spawns 10 energy bolts in a spread pattern.

Testing and Debugging

With everything in place, it's time to test your mod. Launch Doom Eternal with your mod enabled and try out your new BFG-X. Pay attention to the following:

• Does the model appear correctly in-game?
• Are the textures displaying properly?
• Does the primary fire function as expected?
• Does the secondary fire work and balance well with gameplay?

Don't be discouraged if things don't work perfectly the first time. Modding often involves a lot of trial and error. Use the game's console and log files to identify and fix any issues.

Optimizing Performance

Once your mod is functioning, it's crucial to optimize it for smooth gameplay. Here are some tips:

• Reduce polygon count on your 3D model where possible without compromising quality.
• Optimize texture sizes - use texture atlases where appropriate.
• Profile your scripts to ensure they're not causing performance hitches.

Remember, a well-optimized mod is more likely to be enjoyed by other players!

Sharing Your Mod

Congratulations! You've created a custom weapon mod for Doom Eternal. Now it's time to share your creation with the world. Here are some platforms where you can publish your mod:

• Nexus Mods
• ModDB
• Bethesda.net (if they support Doom Eternal mods)

When uploading your mod, include clear installation instructions, screenshots, and a video demonstration if possible. Be open to feedback from the community - it can help you improve your modding skills for future projects.

Conclusion

Creating a custom weapon mod for Doom Eternal is a challenging but rewarding process. It combines elements of 3D modeling, texturing, scripting, and game design, providing a comprehensive learning experience for aspiring game developers.

Remember, the key to successful modding is patience and persistence. Don't be afraid to experiment, and always be open to learning new techniques. The modding community is generally very supportive, so don't hesitate to ask for help if you get stuck.

I hope this guide has given you a solid foundation for creating your own Doom Eternal weapon mods. Now go forth and create something truly hellish!