3dsmax-mcp

A production oriented MCP server that connects AI agents to Autodesk 3ds Max. Works with any MCP-compatible client.

Features

• Native C++ Bridge — 76 handlers running inside 3ds Max as a GUP plugin, 86-130x faster than MAXScript
• One-step installer — uv run python install.py handles everything
• Quad-view capture — Screenshotting is fast and supports multi views.
• Full default tool surface — full MCP profile exposes core and specialty scene/object/material/pipeline tools by default
• 116 tools in full profile across scene, objects, materials, modifiers, controllers, viewport, introspection.
• Bundled MAXScript reference — 10 topic files for agents to write correct MAXScript

Architecture

Agent  <-->  FastMCP (Python/stdio)  <-->  Named Pipe  <-->  C++ GUP Plugin  <-->  3ds Max SDK
                                      |
                                      +--> TCP:8765 fallback --> MAXScript listener

The native bridge runs inside 3ds Max as a Global Utility Plugin. It reads the scene graph directly through the C++ SDK and communicates over Windows named pipes. 76 native handlers for scene, objects, materials, modifiers, controllers, viewport, introspection, and more.

Requirements

• Python 3.10+
• uv
• Autodesk 3ds Max 2026 (2024/2025 supported via MAXScript fallback)

Installation

git clone https://github.com/cl0nazepamm/3dsmax-mcp.git
cd 3dsmax-mcp
uv sync
uv run python install.py

Updating

git pull
uv sync
uv run python install.py

To install without copying or building the agent skill files:

uv run python install.py --skip-skill

MCP Tool Profile

The external MCP server defaults to the full profile so specialty modules such as Data Channel, effects, floor-plan generation, tyFlow, RailClone, wire params, and standalone-chat driver tools are available without extra setup. Use the core profile only when you want a smaller common-tool surface.

$env:MCP_TOOL_PROFILE = "core"
python -m src.server

Skill

The skill file teaches agents how to use the tools, what pitfalls to avoid, and how 3ds Max works. Without it, agents will guess wrong on material workflows, controller paths, and plugin APIs. The installer builds and deploys it automatically.

However Anthropic models seem to REALLY like using maxscript instead of using the native tooling unlike Codex which uses the right tool most of the time.

If you need to rebuild manually:

python scripts/build_skill.py

Safe mode

Both the native bridge and the MAXScript listener read from a shared config:

%LOCALAPPDATA%\3dsmax-mcp\mcp_config.ini

[mcp]
safe_mode = true

When enabled (default), these commands are blocked: DOSCommand, ShellLaunch, deleteFile, python.Execute, createFile

To disable, set safe_mode = false and restart 3ds Max.

Scope — read this

safe_mode is an accident preventer, not a sandbox. It's a case-insensitive substring blocklist, so a determined author (or a sufficiently clever LLM) can bypass it with string concatenation, DotNet reflection, etc. It catches the obvious shapes — LLM hallucinates deleteFile → rejected — not an adversarial MaxScript author.

What it doesn't cover:

• Native C++ handlers run unfiltered: delete_objects, manage_scene (reset/new/open), render_scene, merge_from_file, write_osl_shader, capture_* (disk writes). If the LLM hallucinates them they run.
• The \\.\pipe\3dsmax-mcp named pipe uses the default ACL — any process running as your user can open it and send commands. Fine on a single-user dev machine; if you need multi-user isolation, gate on GetNamedPipeClientProcessId.

The v0.7.0 chat window runs your configured LLM with direct scene-editing tools. Treat it like you'd treat any local agent that can edit your scene: don't point it at scenes you wouldn't double-click, and keep your API key in .env not a shared drive.

Tools

Default full profile: 116 tools across scene management, objects, materials, modifiers, controllers, wiring, viewport capture, file access, plugin introspection, tyFlow, Forest Pack, RailClone, Data Channel, and more. Core profile: 79 tools with concise descriptions.

v0.7.0 — Standalone Chat Mode

Run an AI chat entirely inside 3ds Max — no external MCP client required. The native bridge ships with a Win32 chat window, an OpenAI-compatible LLM client, and direct access to scene tools.

• Launch: You can find chat window in usermacros or search it directly by global search.
• API key: %LOCALAPPDATA%\3dsmax-mcp\.env — OPENROUTER_API_KEY=... (also accepts LLM_API_KEY / OPENAI_API_KEY). Real env vars override the file. deploy.bat seeds .env.example on first install.
• Settings: %LOCALAPPDATA%\3dsmax-mcp\mcp_config.ini [llm] — non-secret knobs only (base_url, model, max_tokens, temperature, plus token controls below). Default target is OpenRouter + anthropic/claude-sonnet-4.6.
• Token controls: external MCP defaults to MCP_TOOL_PROFILE=full plus concise tool descriptions. Standalone chat defaults to prompt_mode=compact, tool_profile=full, include_scene_snapshot=true, max_scene_roots=25, max_prompt_chars=12000, max_tool_result_chars=12000, max_history_tool_chars=1800, max_tool_summary_chars=600, max_display_tool_chars=600, max_tool_loops=4. Use MCP_TOOL_PROFILE=core or tool_profile=core only when you need a smaller tool surface.
• Tools: native tools from src/tools/*.py are auto-registered (generated at build time by scripts/gen_tool_registry.py), plus execute_maxscript as a catch-all. The default chat schema exposes the full profile; the compact registry remains available with tool_profile=core.
• Security: the existing [mcp] safe_mode filter applies — execute_maxscript calls from the chat hit the same keyword blocklist as every other path.
• Skill-aware: the v0.7.0 deploy copies SKILL.md to %LOCALAPPDATA%\3dsmax-mcp\skill\. The chat uses a compact rule summary by default; set prompt_mode=full to inject the deployed SKILL.md.
• Slash commands: /reload, /clear, /help.

Building from source (native bridge)

Only needed if you want to modify the C++ plugin.

Max 2027+ — Visual Studio 2022 (v143), C++20, CMake 3.20+

cd native
cmake -B build -G "Visual Studio 17 2022" -A x64 -DMAX_VERSION=2027
cmake --build build --config Release

Then copy native/build/Release/mcp_bridge.gup to C:\Program Files\Autodesk\3ds Max <version>\plugins\.