studio-mcp

Give your MCP client eyes for LEGO models. An MCP server that renders LDraw files (.ldr / .mpd / .dat) to images with real part geometry — studs, slopes, window glass — using headless Blender and the ImportLDraw addon. The result looks like a BrickLink Stud.io render, with no GUI anywhere in the loop.

Point a vision-capable model at a build and it sees the actual bricks: crossed rotation matrices, floating plates, sunken windows — the kinds of export bugs a geometric proxy render will happily hide.

Quickstart

# 1. install
pip install -e .

# 2. install the LDraw parts library + ImportLDraw addon
studio-mcp-setup

# 3. register with Claude Code
claude mcp add studio -- studio-mcp

Then ask things like "render output/build.ldr and tell me what looks wrong" — the model sees the render, not just the text.

Blender is a prerequisite (see Requirements); it is not installed by studio-mcp-setup.

Tools

azimuths is a comma-separated list of view angles in degrees; each is rendered and the views are stitched horizontally. Elevation is fixed at 22°. Higher samples = cleaner but slower.

Requirements

• Blender 4.x on PATH, or point STUDIO_MCP_BLENDER at the binary. Install it yourself (package manager, blender.org, or a local build); studio-mcp-setup does not install Blender.
• ImportLDraw addon (io_scene_importldraw) in Blender's addons dir — installed by studio-mcp-setup.
• LDraw parts library at ~/.ldraw (or LDRAW_LIBRARY_PATH) — installed by studio-mcp-setup.

Environment variables

Manual setup

If studio-mcp-setup can't detect things automatically:

• LDraw library: download complete.zip and unzip so that ~/.ldraw/parts/ exists.
• ImportLDraw addon: download the latest release from TobyLobster/ImportLDraw and install it via Blender > Preferences > Add-ons > Install, or unzip into ~/.config/blender/<version>/scripts/addons/io_scene_importldraw/. (Launch Blender once first so the config directory exists.)

Troubleshooting

• check_renderer says NOT FOUND: run studio-mcp-setup, or set the relevant env var above.
• No GPU / WSL2 / containers: rendering uses Cycles on CPU, which works headless everywhere — no GPU or display needed. A ~150-part model takes a few seconds at the default 640px / 24 samples.
• "no mesh objects imported": the addon couldn't resolve parts — usually a wrong or incomplete LDraw library path. Re-run setup or check LDRAW_LIBRARY_PATH.
• Addon not enabled: the render script enables it automatically per run; if a manual Blender session complains, enable io_scene_importldraw in Preferences > Add-ons.

Provenance

This renderer was extracted from the prompt2brick project, where it started life as the vision critic's "see the actual model" path. prompt2brick keeps its own vendored copy of the render wrapper and Blender script, but this repo is the canonical source going forward — fixes and improvements to the renderer should land here first and be ported back into prompt2brick.

License

MIT — see LICENSE.