Unity Package for 404-GEN 3D Generator

404-GEN transforms prompts and reference images into 3D assets directly inside Unity.

Project Repo | Website | X

Overview

404-GEN gives Unity creators a built-in window for generating and working with 3D assets:

• Generate 3D Gaussian Splats (3DGS) from text or image prompts.
• Generate Mesh v2 GLB models from image prompts.
• Display, edit, and render Gaussian Splat assets in Unity.
• Add cutouts, convex mesh colliders, and simple shadows to Gaussian Splats.
• Import and export Gaussian Splat .ply files.

3D Gaussian Splatting renders high-fidelity objects using many translucent ellipsoids, or "splats." Each splat stores color, size, position, and opacity data.

Requirements

Requirement	Details
Unity	Unity 2022.3 or newer
Network access	Required for 404-GEN cloud generation
API key	A generic limited API key is included. Users can get their own key at gen.404.xyz
Graphics backend	DirectX 12 on Windows, Metal on macOS, Vulkan on Linux
Package dependencies	Installed by Unity: Burst, Collections, Mathematics, Newtonsoft Json, Editor Coroutines, and glTFast

Installation

1. From the Unity Asset Store, click Add to My Assets.
2. In Unity, open Window > Package Manager.
3. Select My Assets.
4. Select 404-GEN 3D Generator.
5. Click Download, then Import.
6. Keep all files selected in the import window and click Import.
7. Restart Unity before using the plugin.

If you are updating from an older release, remove the previous version before importing the latest package.

Quick Start

1. Open Window > 404-GEN 3D Generator.
2. Choose the output type:
   • 3DGS: use a text prompt or image prompt.
   • Mesh: use an image prompt. Text-only mesh generation is not supported by Mesh v2.
3. For Mesh output, adjust Geometry Quality, Texture Quality, and Face Count if needed.
4. Click Generate.
5. Generated assets are saved to Assets/GeneratedModels by default.

The generation window tracks each job while it is queued, running, and completed.

Output Types

Output	Input	Result
3DGS	Text prompt or image prompt	Gaussian Splat asset created from the generated .ply data
Mesh	Image prompt only	.glb model imported into Unity through glTFast

For prompt guidance, see the 404-GEN Prompt Guide.

Settings

Open Edit > Project Settings > 404-GEN 3D Generator to configure:

• Generated models folder.
• Gateway URL and API key for 3DGS generation.
• Mesh v2 API URL and API key.
• Auto-cancel timeout for long-running prompts.
• Whether deleting a prompt also deletes associated generated files.

The default Mesh v2 settings generate detailed geometry and textures. Lower quality settings can reduce processing time and output size.

Gaussian Splatting Tools

Transformations

Gaussian Splat renderers expose two inspector controls in addition to standard Transform values:

• Splat Scale controls the size of the rendered splats.
• Opacity Scale increases or decreases the opacity of all splats.

Cutouts

Use Add Cutout in the Gaussian Splat inspector to hide or isolate parts of a splat with a box or ellipsoid cutout. Enable Invert on the cutout to render the area outside the shape instead.

Mesh Collider

Use Add Mesh Collider in the Gaussian Splat inspector to add a lightweight convex hull collider generated from the splat positions.

Shadows

Use Add Shadow in the Gaussian Splat inspector to add an invisible convex hull mesh that casts a simple shadow for the splat object.

Import and Export PLY

Use Export PLY in the Gaussian Splat inspector to export the selected splat as a .ply file.

.ply files can be imported by adding them to the project's Assets folder and placing the imported asset in the scene.

A collection of Gaussian Splatting .ply files is available in the 404 Dataset.

Troubleshooting

Symptom	What to try
Mesh generation button is disabled	Mesh v2 requires an image prompt. Select an image before generating Mesh output.
Generated GLB does not import as a model	Confirm the package dependency com.unity.cloud.gltfast is installed by Unity.
Job times out	Increase the timeout in Edit > Project Settings > 404-GEN 3D Generator.
Job reports unauthorized	Check the API key in Project Settings, or get a user API key at gen.404.xyz.
Rendering issues	Confirm the recommended graphics backend is enabled for your platform.

For questions or help troubleshooting, visit the Help Forum in the 404-GEN Discord Server.

License

This package is distributed under the MIT License.