Best way to 3D level design in Godot?

We are going to use 2 tools to make our levels in Godot: TrenchBroom + Qodot

TrenchBroom (or TrenchBroom 2, or TB) is a free open-source cross-platform 3D level editor with modernized Quake-style brush-based construction and ongoing updates / support. It is widely used across several modding communities as well as commercial projects.

Qodot extends the Godot editor to import Quake .map files, and provides a data-driven framework for converting the entities and brushes contained therein into a custom node hierarchy.

Keep in mind, there are two versions of Qodot:

- Qodot 3 (Legacy)

- Qodot 4

Qodot 3 Setup

Prerequisites

The latest build of Godot 3.x, mono not required.

Installation

1 - Search for “Qodot” in the Assetlib.

2 - Download and install the plugin

3 - Go to Project > Project Settings > Plugins, then enable Qodot.

Qodot 4 Setup

Prerequisite Steps

Use Godot Engine .NET / mono build.

Download .NET SDK for your OS, must be .NET SDK 7.0 or higher.

Run the .NET SDK installer, ensure it completes successfully.

Installation

1 - Open any Godot project with the mono engine.

2 - Search for “Qodot” in the Assetlib

3 - Download and install the plugin. /qodot/textures can be ignored to save on filesize and import time.

4 - Go to Project > C# > Create C# Solution. Then click Build in the top-right corner.

5 - Go to Project > Project Settings > Plugins, then enable Qodot.

Once Qodot is installed you should see a folder called "addons" in your root directory.

TrenchBroom Setup

This guide is for Godot 3.x:

1 - Download TrenchBroom for Windows here

2 - In Godot, in your root directory, go to addons/qodot/game_definitions/trenchbroom/qodot_trenchbroom_config_folder.tres

3 - In the inspector, click on Trenchbroom Games Folder and then look for the folder "TrenchBroom\games" in your hard drive:

4 - Click on Export File "On" (it looks like a checkbox, but actually is a button)

5 - To keep your project tidy, you should create a folder called "Maps" (or whatever name is suitable for you).

6 - Open Trenchbroom, click on "New Map" and select "Qodot". Create a map as you like.

7 - To export a trenchbroom map to Godot, go to  File/Save Document and save the map in the Maps folder in your Godot project.

8 - In Godot, create a new scene and create a new "Qodot Map node"

9 -  In the Inspector, select the map file you created:

10 - Select "Quick Build"

11 - Enjoy!