Weaponizing vehicles

How to weaponize a custom vehicle

Summary

Published: Mar 29 2025 by MisterChedda Last documented edit: Mar 30 2025 by manavortex

This page will teach you how to turn a civilian car into a weaponized vehicle by copying the correct properties from a car that is already combat-ready.

Wait, this is not what I want!

• Check Boe6's Guide: basic car from A to Z for how to add your own car from scratch

• Check Windows & Doors opening + MountedWeapons clue for instructions on modifying the combat behaviour

• Check Cheat Sheet: Vehicles and the surrounding pages for a list of vehicle-related things that you might want to look up

Prerequisites

• You have created a Wolvenkit Project

• You have a text editor such as Notepad++

• You have Wolvenkit 8.16.2 (or a Nightly if that doesn't have released yet)

Step 0: Add the reference files

Decide which car you want to stealborrow the weapon from, then add its .ent and .app file to your project for easier reference (you can look them up on Cheat Sheet: Vehicles).

For this project, we're using the Hellhound, and the corresponding files are

base\vehicles\standard\v_standard3_militech_hellhound__basic_01.ent
base\vehicles\appearances\standard\militech_hellhound__basic.app

These will be called "reference files" through the rest of the guide.

Step 1: Changing the .ent file

This file is where your game looks up your car when spawning it from its record. You can learn more about Entity: .ent files on the link, but you don't have to!

1. Changing the car's type

We need to change your car's type to a weaponized vehicle. Here's how we do that:

1. Open your car's .ent file and the reference file, and set the editor difficulty mode to "advanced".

2. Select entity in the reference file. Right-click and select "Copy Handle".

3. Select entity in your car's file. Right-click and select "Paste as Handle".

   This will only be available in Wolvenkit ≥ 16.2 or the Nightly. If you're on an older version, you'll have to do the edit via JSON.

4. Save the file (Hotkey: Ctrl+S)

2. Adding the weapon slots

1. In both files, open the components array and find the vehicle_slots component. It should be close to the top of the list.

2. In the reference file, scroll to the bottom of the list and find the entSlot entries corresponding to the car's weapons.

3. Select them, then right-click and copy the selection.

4. In your file, select either the list or an item in the list, and paste the selection here.

5. Save the file.

3. Adding the attachment slots

1. In the reference .ent, find the gameAttachmentSlots component (it will probably be called AttachmentSlots).

2. Copy it and paste it into your .ent file

4. Adding the effect

1. In the reference file, search for effect components. Look for entEffectSpawnerComponent s. In the hellhound, this is called fx_explosion.

2. Select and copy it.

3. Paste it into your car .ent's components array.

4. Save the file.

Step 2: Changing the tweak record

This file is used by TweakXL to make changes to the game's static database — for example, changing a car. If you want to learn more about tweak modding, you can check out Tweak modding: Guides, but be vareful. This rabbit hole runs deep.

.yaml files use indentation (the number of spaces at the beginning of a line) to organize entries in groups. This is easy to break!

If you run into problems, you can check your file by validating it (e.g. on yamllint.com). If that doesn't help, you can check red4ext/plugins/TweakXL/TweakXL.log for error messages.

1. Adding the file

You can skip this step if you already have a yaml file.

1. In Wolvenkit's Tweak Browser, find the car's record that you want to change

2. Right-click and select "Add TweakXL override"

3. Do the same for the record that you're stealingcopying from.

4. In your project's Resources section, find the .yaml file and look at it. Then, delete all properties but the following:

   • vehDataPackage

   • weapons (your car might not have it)

2. Adding the weapons

1. Find the weapons array in your reference yaml and copy it to your own files.

2. You can delete those entries that you don't want

3. Delete the reference yaml, you don't need it anymore!

3. Changing the combat behavior

Now, you'll have to tell your car that it's a weaponized vehicle. Do that by modifying the vehDataPackage. (Thanks to boe6 for pointing it out!)

You can do this in-line:

  vehDataPackage:   
    $base: Vehicle.VehicleDataPackageDefault
    driverCombat: DriverCombatTypes.MountedWeapons

Step 3: Changing the .app file

This file is loaded by the .ent file, and contains an item's different appearances. You can learn more about Appearance: .app files at the link, but you don't have to.

Open your car's .app file and the reference .app file.

1. Adding visual tags

For every appearance in your .app file, you need to add the combat-related visual tags (you can ignore faction tags such as Nomad or NCPD).

DualPowerWeaponPosA
MissileWeaponPosA

They look like this:

2. Adding the actual weapons

1. From your reference .app, find the weapon's mesh component(s) (you can for example filter for turret):

1. Copy them

2. Paste them into your own car's .app appearance(s)

3. Your car now has weapons.

3. Adjusting the weapon positions

To find the right offsets, check Placing lights and effects. The process is the same here - although the offsets are finicky and you'll probably end up falling back to trial&error.

You can adjust your wepaon's position relative to the car in two places:

The weapon's origin

In the .ent file's vehicle_slots slot (Step 1.2), find the relativePosition and relativeRotation properties. These control where your rockets / your gunfire is coming from.

• In the mesh component that you just copied (Step 3.2, localTransform property)

The weapon mesh's position

In the .app file inside the ent(Physical)MeshComponents that you have copied:

• change the localTransform property

• make sure that the parentTransform points at the bindName vehicle_slots and the slotName Base

If parts of your weapon mesh are disconnected and/or on the ground

That is becauuse they're rigged to a bone that your car does not have. The easiest way to fix this is to export their mesh into Blender and (in Edit mode) assign all weights to the first group.

You can check Weight Painting for Gonks for more detail about that.

Making the weapons move

To be done

Delete the reference files

Before you release your mod, do not forget to delete the reference files that you added in step 0. Never include files in your .archive that don't need to be there!