dcc-mcp-cinema4d

Typed Cinema 4D document automation for DCC-MCP, executed through Maxon's licensed headless c4dpy runtime.

Illustrative workflow limited to the adapter's implemented primitive, transform, validation, render, and interchange operations; generated source is retained in docs/images/dcc-mcp-cinema4d-showcase-source.png.

Part of the DCC-MCP host matrix

dcc-mcp-cinema4d — Cinema 4D adapter for typed headless modeling, interchange, inspection, and rendering.

It is one of 47 host adapters in the DCC-MCP catalog. Every adapter speaks the same MCP protocol and builds on the same core runtime contract; each one exposes the tools its own host needs on top of that.

• All host adapters and install metadata
• Host matrix on the core README
• Showcase

This block is generated from the catalog entry in dcc-mcp-catalog.yml. Re-run the generator after changing the catalog.

Capabilities

• Discover and report the real Cinema 4D, Python, and API versions.
• Create, inspect, validate, and atomically copy .c4d documents.
• Add typed cube, sphere, cylinder, cone, torus, and plane primitives.
• Set absolute translation, HPB rotation, and scale; remove named objects safely.
• Import C4D, OBJ, FBX, glTF/GLB, STL, Alembic, Collada, and 3DS geometry when the installed Cinema 4D runtime provides the corresponding importer.
• Export full documents to C4D, OBJ, FBX, glTF/GLB, STL, Alembic, or Collada when the installed runtime provides the corresponding exporter.
• Render bounded PNG and JPEG images without a GUI.

The adapter never accepts arbitrary Python source. Every host call executes a packaged, allowlisted driver in a fresh c4dpy process with bounded paths, timeouts, output streams, and response size. Document mutations use a staged file and atomically replace the durable document only after a successful host operation.

OBJ import and export form the production-validated interchange baseline. Other formats are runtime-dependent; get_capabilities reports this boundary and unavailable optional importers or exporters fail with a format-specific error.

Requirements

• Cinema 4D R21 or newer with a valid license.
• The matching c4dpy executable shipped with that Cinema 4D installation.
• Python 3.9 or newer for the DCC-MCP service.
• dcc-mcp-core>=0.20.36,<1.0.0 in the same Python distribution.

Maxon documents that c4dpy is a headless Cinema 4D instance capable of loading, constructing, saving, and rendering scenes, but it requires a real Cinema 4D installation and license.

Two interpreters

The adapter spans two Python runtimes. Most setup confusion comes from mixing them up:

The service floor is this package's requires-python. The host floor is decided by whichever interpreter that Cinema 4D build ships, and releases whose c4dpy is Python 2.7 (the R21 and R22 lines) cannot run the driver. That makes R23 the effective floor in practice, even though the build floor is R21.

doctor --json reports both: checks.runtime.python_version is the host side, and plan.python.version is the service side.

Host versions and read-back

Declared support lives in src/dcc_mcp_cinema4d/compat_matrix.json, shipped in the wheel and keyed on the integer from c4d.GetC4DVersion(). doctor and verify embed the verdict as host_matrix; a build outside the matrix is rejected explicitly rather than treated as "close enough".

Every mutating tool reads its change back before reporting success — document mutations against the reopened document, exports against their format signature, renders against the requested dimensions — and a mismatch raises an error naming the tool, the check, both values, and the Cinema 4D build.

CI runs pytest -m "not cinema4d", so its evidence is contract level: the read-back logic is proven, Cinema 4D's behaviour is not. Host-level evidence comes only from the opt-in real-host test on a licensed machine. See install.md.

Install

See install.md for the official Core Install SOP contract, identity-bound planning, atomic receipt, verification, upgrade, uninstall, and troubleshooting.

python -m pip install dcc-mcp-cinema4d
dcc-mcp-cinema4d plan --target install --c4dpy <absolute-c4dpy-path> --json
dcc-mcp-cinema4d install --c4dpy <absolute-c4dpy-path> --json --yes
dcc-mcp-cinema4d doctor --c4dpy <absolute-c4dpy-path> --json

Set the licensed runtime and allowed workspace before starting the adapter:

$env:DCC_MCP_CINEMA4D_C4DPY = "C:\Program Files\Maxon Cinema 4D 2026\c4dpy.exe"
$env:DCC_MCP_CINEMA4D_ALLOWED_ROOTS = "D:\projects;D:\exports"
dcc-mcp-cinema4d

For an explicit standalone readiness check:

dcc-mcp-cinema4d verify --c4dpy "C:\Program Files\Maxon Cinema 4D 2026\c4dpy.exe" --json

Lifecycle execution binds the exact Maxon product/file identity, digest, selected Python distribution, live PID/start token, and adapter-owned receipt. The default allowed root is the adapter's current working directory.

Agent workflow

dcc-mcp-cli list
dcc-mcp-cli search Cinema 4D status --dcc-type c4d
dcc-mcp-cli load-skill cinema4d-session --dcc-type c4d --instance-id <id>
dcc-mcp-cli describe c4d.<id>.get_status
dcc-mcp-cli call c4d.<id>.get_status --json '{}'

Load cinema4d-modeling only when modeling, interchange, or rendering tools are needed. Use --wait for document operations because they run as bounded asynchronous jobs.

Development

python -m pip install -e ".[dev]"
python -m ruff check src tests
python -m ruff format --check src tests
python -m pytest -m "not cinema4d"
python -m build
python -m twine check dist/*

Real-host acceptance requires a licensed c4dpy; CI intentionally does not mock a Maxon license. On a licensed machine:

C4D_TEST_EXECUTABLE=/path/to/c4dpy python -m pytest -m cinema4d

That is the only host-level evidence this adapter produces, and it is opt-in precisely because the license cannot be provisioned on a hosted runner.

Official references: c4dpy manual, Cinema 4D Python SDK.