MeshRight

Check and fix 3D scans and models for printing. Free, simple, and on your own computer.

MeshRight is a free, open source alternative to Meshmixer's repair tools (Meshmixer is no longer developed). It is made for people who 3D print scans and downloaded models and want one simple tool instead of several. It runs on Windows, macOS and Linux, and opens in your web browser, but everything happens on your own computer.

Status: early alpha. Everything below works; expect rough edges. Please report problems with an example file.

Start in 60 seconds

1. Download the app for your computer from the Releases page and double-click it. MeshRight opens in your web browser.
2. Drop a model or scan onto the page, or click a sample model.
3. Read the score and the problems list, then work down the checklist on the right. Press ? at any time for help.

In three steps

1. Open a scan or model. MeshRight checks it and gives it a score from 0 to 100, with every problem explained in plain English and shown on the model.
2. Follow the checklist: Fix problems, Stand it up, Fits your printer, Export for your slicer. Each step is one button, and every change can be undone.
3. Print: export a file, or open it straight in your slicer.

No settings to learn, no account, and your files never leave your computer.

Problems shown on the model	Clean up shows its plan first	Which way is up?

What it can do

Check

• Opens STL, 3MF, OBJ, PLY, GLB/glTF, OFF, AMF and USD (USDA, USDC, and USDZ as made by iPhone Object Capture), and turns point clouds (XYZ, ASC, PTS, E57, LAS, LAZ) into a surface. Wrong units and phone-scan orientation (metres, Y up) are fixed automatically. The downloaded app reads all of these except binary USD (USDC, and some USDZ), which needs a large extra reader: export those as OBJ, GLB or USDA, or see Install. FBX cannot be read; MeshRight says what to export instead.
• Says which scanner made a file (Revopoint, Creality, Shining 3D, Polycam, Scaniverse, KIRI, Luma and others) and what its scans usually need.
• A print-readiness score and a plain-English list of problems: holes, edges shared by too many triangles, surfaces cutting through themselves, inside-out parts, loose crumbs, walls too thin to print.
• Problems are shown on the model, plus a Cut view, an Overhangs view and a Rough spots view.
• Show what changed: after repairs, the model turns green where it is untouched and red where the surface moved, compared with your original file.

Fix

• Clean up in one click. It shows its plan first; choose Quick print, Balanced, Keep all detail or Flexible (for TPU, which then gets a stricter wall check).
• Make Solid rebuilds badly broken models as one closed solid.
• Give it thickness turns an open surface (a face scan, a mask) into a printable shell.
• Sculpt brushes: smooth rough spots, flatten, push out or in.

Stand it up

• Which way is up? offers pictures of likely bottoms; or click the bottom yourself.
• Best way to print compares placements for fewest supports, strongest part and fastest print.
• Warns when a model would tip over, and offers to cut the bottom flat or add a flat foot (which keeps the whole model).

Fit your printer

• Pick your printer once from a list, or enter its bed size.
• Too big? The checklist offers both: shrink it to fit, or split it into parts that fit, with pins so they line up when glued. Cut in two anywhere with a plane you slide.
• Numbered parts: each part's number is engraved on a cut face (hidden once glued), in assembly order, and MeshRight tells you which parts join.
• Show a coin for scale beside the model to picture its real size.

Edit

• Erase an area or a loose piece, drill holes, measure (and resize from a known distance), hollow for resin with drain holes.
• Make a bust from a head scan: closes the neck, cuts it flat, adds a base.
• Make a part that fits your scan (a pad, a grip, a cover).
• Combine models: join a stand or handle on, or cut a shape out.
• Merge scans taken from different sides into one model.

Colours and export

• Keeps colours from colour scans through every repair.
• Print in colours (Export, then 3MF in colours): a 3MF painted for a multi-colour printer. MeshRight groups the scan's colours into 2 to 8 print colours and paints every triangle, so Bambu Studio, OrcaSlicer and PrusaSlicer open it ready to print. You only match each colour to a filament.
• Export STL, 3MF, OBJ or PLY, or open it straight in Bambu Studio, OrcaSlicer, PrusaSlicer, UltiMaker Cura or Creality Print.
• Save a project (.meshright) to carry on later.

And

• Up to four models open at once, in tabs (the oldest closes when you open a fifth). Files up to 1000 MB; very big files can be cancelled while they open.
• Fix many files at once, in the app or from the command line.
• Ask AI (optional): connect any AI service you already use, or a free one on your own computer, and ask about your model in plain words. See Ask AI.
• Works with AI apps: meshright mcp offers the checks, Clean up and every action to Claude Desktop, Claude Code, Cursor and other MCP apps (see Use).
• Sample models, first-time tips and keyboard shortcuts (press ?).
• Runs on your own computer and works offline. The only thing it asks the internet is GitHub's latest version number, once a day (you can switch that off).

Ask AI

MeshRight works fully without AI. If you want, you can connect an AI service and ask questions such as "why won't this print?" or "make it 15 cm tall and fix it". Click Ask AI at the top of the page. The first time, choose a service:

• On your own computer, free: Ollama or LM Studio. Install one, download a model (for example qwen3:8b in Ollama), and choose it in MeshRight. No key needed and nothing leaves your computer.
• A service you pay for: OpenAI, Claude (Anthropic), Google Gemini, OpenRouter, DeepSeek, Mistral or Groq. Paste your API key from that service's website.
• Anything else that speaks the OpenAI chat format: choose Other and type its address.

What the AI can do:

• Explain the check report in plain words and answer questions about it.
• Suggest steps from MeshRight's own tools, such as Clean up, Set size, Put on bed, Hollow or Make a bust. You see each step with its reason and tick the ones you want. Nothing changes until you press Apply, and each step shows in the history and can be undone.

What it cannot do:

• See your model. It is sent the check report (score, sizes, the list of problems), your printer settings and your question, never the model file.
• Use the tools that need you to click on the model (erase an area, sculpt, merge scans). It tells you when you need one of those.
• Change anything by itself, or invent tools: any step that is not a real MeshRight tool with sensible settings is dropped before you see it.

Your key is stored only on this computer, in a settings file only your user account can read, and is never shown in the page again. Forget in AI settings deletes it. You can also leave it out of the file and set the MESHRIGHT_AI_KEY environment variable instead.

From the command line:

meshright ask model.stl "will this print on my printer?"
meshright ask model.stl "make it 50 mm tall" --provider ollama --model qwen3:8b

Install

Easiest: download the app for your computer from the Releases page: MeshRight-windows.exe, MeshRight-macos or MeshRight-linux. Double-click it and MeshRight opens in your web browser. Nothing else to install. The app includes the E57 and LAS/LAZ readers and the AI-app (MCP) server.

The apps are not signed yet. On Windows choose More info, then Run anyway. On a Mac, right-click the file and choose Open the first time. On Linux, allow the file to run as a program (right-click, Properties, Permissions).

With Python (3.10 or newer):

pip install meshright

Optional extras, in square brackets: e57 (E57 scans), las (LAS and LAZ scans), usd (binary USD, a large download), mcp (AI apps). For example:

pip install "meshright[e57,las,mcp]"

To run the latest code from this repository instead:

git clone https://github.com/Huzy85/MeshRight.git
cd MeshRight
pip install .

Needs: Windows 10 or newer, macOS 12 or newer, or a recent Linux, on a 64-bit computer. 8 GB of memory handles most scans; very big scans (several million triangles) want 16 GB. Any modern browser. The apps are built for Intel and AMD processors and Apple Silicon Macs; ARM Windows and ARM Linux are untested.

Use

Open the app in your browser:

meshright

Options for the app:

meshright serve --port 8766      # use another port if 8765 is busy
meshright serve --no-browser     # start without opening a browser window

--host 0.0.0.0 lets other devices on your network open MeshRight. There is no password, so only do this on a network you trust, and list the names they will use in MESHRIGHT_ALLOWED_HOSTS (comma-separated). Anyone who can reach it can also use your Ask AI connection. MESHRIGHT_MAX_UPLOAD_MB changes the 1000 MB file limit.

Check files or whole folders from the command line:

meshright check model.stl other_model.3mf
meshright check scans/
meshright check model.stl --json

meshright check exits with code 1 when any file needs repair, so it can be used in scripts.

Fix a whole folder (the fixed files and a report go into meshright-fixed):

meshright fix scans/
meshright fix scans/ --format stl --best-bottom

Let an AI app use MeshRight. MeshRight is an MCP server, so Claude Desktop, Claude Code, Cursor and other MCP apps can check a file, run Clean up or any single action, export a colour scan painted for a multi-colour printer, and read your printer settings, all on your own computer. Print the settings to paste:

meshright mcp --show-config

It prints the lines and says where they go for each app (for Claude Desktop: Settings, Developer, Edit Config). From the downloaded app, run the same command against the app file, for example MeshRight-windows.exe mcp --show-config. The AI app writes its results next to your file, or where it is told to. It will not replace an existing file unless it passes overwrite, and it never replaces the original.

Troubleshooting

• The browser does not open. Go to http://127.0.0.1:8765 yourself.
• "Port 8765 is busy". MeshRight may already be running in another window. Close it, or start with meshright serve --port 8766.
• Windows says it protected your PC. The app is not signed yet. Choose More info, then Run anyway.
• macOS says the app cannot be opened. Right-click it and choose Open.
• A big scan is slow. Use Reduce detail first. Above about 3 million triangles every change takes a while.
• An FBX or binary USD file will not open. Export it as OBJ, GLB or STL from the app that made it (Blender: File, Export).
• Something else went wrong. Your model is never changed by a failed step. Please report it with the file if you can.

Privacy

Everything happens on your own computer. MeshRight has no account and no tracking. It contacts the internet for two things only: GitHub's latest version number, once a day (switch it off in Help), and, only if you set it up, the AI service you chose in Ask AI, which receives the check report and your question, never the model.

Words used

• Triangle: models are made of thousands of small flat triangles joined edge to edge.
• Hole: a gap where triangles are missing. Printers need a closed surface.
• Slicer: the program that turns a model into instructions for your printer (Bambu Studio, PrusaSlicer, Cura and others).
• Support: extra plastic printed under overhanging parts and removed afterwards.

What's new

See CHANGELOG.md.

Contributing

Contributions are welcome, from bug reports with example files to new repair tools. See CONTRIBUTING.md.

Licence

MeshRight is free software under the GNU GPL v3. In plain words: you can use it for anything, including models you sell, and share it freely. If you share a changed version of MeshRight itself, you must share its source code under the same licence. The bundled three.js library is MIT licensed.