Cognito 3D

Local image-to-3D generation for MCP clients.
Turn one or more reference images into a GLB through a small, model-agnostic tool surface.

Cognito-3D-MCP

Cognito-3D-MCP is a local Model Context Protocol server that gives AI agents a consistent way to create 3D assets from images. It routes each request to one of three generation engines while keeping model files, input images, and generated meshes on your machine.

The server currently integrates Hunyuan3D-2mv as its built-in multiview engine, with optional Stable Fast 3D and SPAR3D adapters for single-image generation.

Why Cognito

• One tool surface — switch generation engines without changing MCP clients.
• Multiview input — provide front, left, back, and right references when using the default engine.
• Local by design — images and generated GLB files remain in paths you control.
• Backend discovery — clients can inspect which engines are configured before starting a GPU-heavy job.
• Safe runtime isolation — optional engines run in their own Python environments to avoid native dependency conflicts.
• Reproducible controls — configure seed, inference steps, guidance, mesh resolution, and texture resolution through the MCP call.

How it works

flowchart LR
    Client["MCP client"] --> Server["Cognito-3D-MCP"]
    Server --> Discover["list_3d_backends"]
    Server --> Generate["generate_3d"]
    Generate --> MV["Hunyuan3D-2mv<br>1–4 views"]
    Generate --> SF3D["Stable Fast 3D<br>1 view"]
    Generate --> SPAR["SPAR3D<br>1 view"]
    MV --> GLB["Local GLB"]
    SF3D --> GLB
    SPAR --> GLB

GPU generation jobs are serialized so multiple MCP calls do not compete for the same device.

Requirements

• Python 3.10 or newer
• A PyTorch installation supported by your hardware
• The dependencies and model access required by the generation engine you intend to use
• An MCP-compatible client such as Codex, Claude Desktop, or another local host

The default engine is GPU-oriented and normally expects CUDA. Model weights are not stored in this repository.

Install

git clone https://github.com/Lanc3/Cognito-3D-MCP.git
cd Cognito-3D-MCP
python -m pip install -e ".[mcp]"

Copy .env.example into your environment configuration and adjust the paths for your machine. The default settings use the Hunyuan3D-2mv checkpoint:

HUNYUAN3D_MODEL_PATH=tencent/Hunyuan3D-2mv
HUNYUAN3D_SUBFOLDER=hunyuan3d-dit-v2-mv
HUNYUAN3D_VARIANT=fp16
HUNYUAN3D_DEVICE=cuda

HY3D_MCP_OUTPUT_ROOT=outputs/mcp
HY3D_MCP_JOB_TIMEOUT=1800

Run the server over stdio:

cognito-3d-mcp

You can also run it as a Python module:

python -m hy3dgen_mcp.server

Connect an MCP client

Use an absolute repository path in your client configuration:

{
  "mcpServers": {
    "cognito-3d": {
      "command": "python",
      "args": ["-m", "hy3dgen_mcp.server"],
      "cwd": "/absolute/path/to/Cognito-3D-MCP"
    }
  }
}

Restart the client after changing its MCP configuration.

Tools

list_3d_backends

Reports each engine's availability, configuration summary, and whether it is the default. Call this first when the client should choose an engine dynamically.

generate_3d

Creates a GLB from local image files.

Parameter	Purpose	Default
front_image	Absolute path to the required front image	Required
backend	hunyuan3d, sf3d, or spar3d	hunyuan3d
left_image	Optional left reference for the multiview engine	—
back_image	Optional back reference for the multiview engine	—
right_image	Optional right reference for the multiview engine	—
output_dir	Destination directory for the generation job	Auto-generated
seed	Reproducibility seed	12345
steps	Inference steps, from 1 to 200	50
guidance_scale	Model guidance strength	5.0
octree_resolution	Mesh extraction resolution, from 32 to 1024	384
texture_resolution	Texture size for supporting engines, from 256 to 4096	1024

Accepted input formats are PNG, JPEG, and WebP. Only the default hunyuan3d engine accepts the optional left, back, and right views. Successful calls return the backend name, output path, input views, and a status message.

Generation engines

Engine	Input	Integration
Hunyuan3D-2mv	1–4 canonical views	Built in and selected by default
Stable Fast 3D	Single front image	Optional isolated installation
SPAR3D	Single front image	Optional isolated installation

To enable Stable Fast 3D or SPAR3D, install the engine from its official source in a separate environment, then configure its repository root and Python executable:

SF3D_ROOT=/absolute/path/to/stable-fast-3d
SF3D_PYTHON=/absolute/path/to/sf3d/environment/python

SPAR3D_ROOT=/absolute/path/to/stable-point-aware-3d
SPAR3D_PYTHON=/absolute/path/to/spar3d/environment/python

Cognito-3D-MCP does not download or redistribute those projects or their model weights.

Output

Each job writes mesh.glb into a unique directory under outputs/mcp/ unless output_dir is provided. Generated outputs are excluded from Git by default.

Development

Run the focused MCP test suite with:

python -m unittest discover -s tests -v

See CONTRIBUTING.md for contribution guidance and SECURITY.md for private vulnerability reporting.

License and provenance

Cognito-3D-MCP is built on imported Hunyuan3D inference source and remains subject to the bundled LICENSE and NOTICE. Those terms include use, territory, distribution, and attribution restrictions, so this repository is source-available and is not represented as OSI-approved open source. Optional engines have their own licenses and model-access terms.

See UPSTREAM.md for the exact upstream repository and pinned commit used by this project.