Work with Claude

Claude can work with the scene that is open in MeshOptimiser. You describe the job in plain words. Claude looks at the scene, selects, hides and explodes parts, and, with your permission, reduces triangles, repairs meshes, renames, moves and exports. It does this through the app, in your window, so you watch it happen.

It uses the same tools you would click, so it saves clicking, not judgement: you still decide what loss is acceptable, and you should look at the result. If you already know which buttons to press, pressing them yourself is just as fast. It is most useful for repeated clean-up, a size to reach, or a folder of files. A general 3D program such as Blender can be driven by Claude in a similar way; MeshOptimiser opens STEP and IGES CAD files directly and has its own finders for bolts and for parts nobody can see.

Claude can also work with the notes people leave on the model. It reads the open ones first (list_notes, get_note), answers with reply_to_note, leaves its own (add_note) on what it flagged or kept, and resolves one only when what it asks is done (update_note). It writes under the name Claude, every step is one undo step that shows in the note’s history, and it never signs a scene off: approving or asking for changes is yours.

Connect it

1. Start MeshOptimiser and open a model.
2. Open Settings with Ctrl, and choose Claude.
3. Turn on Let Claude connect. A Claude connected pill shows in the top bar while it is on.
4. Once, in a terminal on the same computer, add the app to Claude:

If the launcher printed a different port, use that number. Another program that supports MCP over HTTP takes the same address. The Claude section of Settings has a button that copies the command, and its top line says whether the app is off, listening, working or waiting for you. The same word sits beside Claude in the list on the left.

What to ask

• “Find all the bolts and hide them.”
• “Get this under 300,000 triangles and tell me what you took out.”
• “Show it exploded 50% and take a screenshot.”
• “Which ten parts carry the most triangles?”
• “Rename every part that starts with body to Housing.”
• “Stand the model on the floor and make a turntable video.”

What stays in your hands

• By default, anything that changes the model shows an Allow or Don’t allow prompt first. Looking, selecting, hiding, isolating, exploding and moving the camera do not.
• Each kind of change can be set to Allow, Ask first or Block in Settings, Claude. Switching Ask before Claude edits off in the badge’s dropdown lets everything through without asking, deleting included; Always ask before deleting puts the question back for deleting alone.
• Every change is a step in the undo history. CtrlZ takes it back. See Undo and redo.
• Nothing happens until you switch Let Claude connect on, and nothing can reach the app after you switch it off.

The switches

Let Claude connect

The app listens for Claude while this is on. Off, it asks for nothing and nobody can reach it.

Connect when the app opens

If it was on last time, it switches itself on again when you open the app.

Change the model

Reduce triangles, remove holes, remove hidden faces, repair, clean up, merge, split and duplicate.

Move, rename and group

Move, turn and scale parts, recentre the model, stand it on the floor, rename parts, make and dissolve groups.

Delete parts

Delete chosen parts, or every part under a size.

Open files and save exports

Open a file from this computer, save exports and turntable videos into the app’s exports folder.

Ask before Claude edits

The Allow or Don’t allow prompt before every change to the model. It is in the badge’s dropdown and in Claude mode, not in Settings, and sets all four kinds above at once.

Always ask before deleting

In the badge’s dropdown. Keeps the prompt for Delete parts alone when the switch above is off.

Show the Claude pill in the top bar

A small pill that says when Claude is listening, working or waiting for you.

Show a note when Claude acts

A short message names what Claude is doing.

In Settings, each of the four kinds of change has three buttons: Allow (just do it), Ask first (the prompt; this is how it starts) and Block (turned off). A kind that is blocked, or a switch that is off, refuses the request, and Claude is told why.

The badge in the top bar

While Claude is connected, a Claude connected badge sits at the right of the top bar. Click it for a dropdown: whether the app is listening, working or waiting for you, the number of requests, how many were done, declined or failed, the last three requests with how long each took, and three switches: Let Claude connect, Ask before Claude edits and Always ask before deleting. Copy command copies the connect command, Console opens the console, and More… opens Settings, Claude. Esc or a click elsewhere closes it.

What Claude asked for

At the bottom of the Claude section, This session counts the requests and names the ones asked for most, with how long each takes, and Recent requests lists what Claude asked for and what happened: done, you said no, turned off, or failed. Copy report puts the numbers and the recent requests on the clipboard, for a bug report. Every request and every change of the connection is also written to the console (the button in the status bar), tagged claude, and to the window that runs the app.

Knowing where it stands

Before it changes anything, Claude can check the model in one call (check_model: where the weight is, what is tiny, thin, hidden or drawn twice, the unit, and what to do first) and say what the file would weigh against the app’s own guidelines (estimate_export_size: about 5 MB and 100,000 triangles for a web page, 15 MB for Shopify, 10 MB and 100,000 triangles for Apple AR Quick Look, 25 MB and 200,000 triangles for a phone app). Afterwards optimisation_report gives the file as it was opened against now, with the change in percent. If you have saved Smart optimise recipes, Claude can list them (list_recipes) and run one (run_recipe) instead of choosing settings itself, and save_scene keeps a scene file before a drastic step.

It can also select by shape, colour or material (select_similar, select_by_colour, select_by_material), list the materials, and add standard parts from the library (add_library_part).

Longer jobs

Some jobs are big, so Claude has a few ways to make them easier to trust. A dry run (dry_run on a step that removes or reduces something) does the step, reads the numbers and takes it back with undo: Claude can tell you “this would save this many triangles” without anything staying changed, and nothing is asked because nothing is kept.

optimise_to_target takes the whole scene to a size or a place (web, Shopify, AR or a phone, or a number of megabytes or triangles) in one call: it tidies up, runs Smart optimise, then reduces the triangles in rounds against the app’s own size estimate. It says whether it got there, why it stopped if not, and how many undo steps it took.

compare_images puts the model as it was opened next to the model now, with the same camera and the triangles, parts and size under each, in one picture saved in the exports folder. It steps back through the undo history to draw the original and forward again, so the scene ends exactly as it was.

list_folder lists the model files in a folder and batch_optimise does them one after another: each file opens in a scene tab of its own, is optimised (a saved recipe, a goal or Smart optimise), is exported as name_optimised and its tab is closed. The scene you have open is not touched. Try one file by hand first.

While a long job runs, the badge in the top bar says which step it is on and the dropdown shows a progress bar with a Stop button. Cancelling in Claude stops it too. The job ends after the step it is on and says what was done.

Pictures for a client

Claude can make clean pictures of the model with the tool render_image: big (up to 8192 pixels a side), drawn at twice the size and scaled down so the edges are smooth, in one angle or several (perspective, front, side, top), in solid, clay, CAD, wireframe, x-ray or the heat view, on a white, light, grey, dark or black background or on none at all (a transparent PNG). The model is framed to fill the picture and the grid is left out. Each picture is saved as a PNG in the exports folder next to the app, and Claude looks at a small preview of it. For a before and after, ask for the same pictures before and after you optimise: the camera, the look and the size are the same.

The quick tool screenshot is a look at the viewport exactly as it is. Claude can also frame the picture on the whole model or on the selected parts: it is then fitted edge to edge on the geometry itself, the move handles are left out, and your own camera is put back afterwards. turntable_video saves one slow turn round the model.

What Claude already knows

Claude does not start from nothing. The app gives it the know-how of an experienced user, so it works in the order a person would and asks the questions a person would ask.

• Six playbooks: how to optimise (the rules and the order of work), recipes by goal (web viewer, AR, a game engine, 3D printing, sending to a customer, a review), judgement (what makes a scene heavy, what each step costs in looks, when to ask), the tools by job, what is safe, and what to do when something fails.
• More than seventy of the app’s own help articles, the same ones you can read here. Claude searches them by words or by a symptom, and reads only the one it needs.
• Ready-made jobs it can start from: optimise for the web, lighten it in one go, take the bolts out, make it safe to send, pictures for a client, review the scene.
• A hint on every tool that says whether it only reads or changes the model, which Claude’s own program uses to decide what to ask.

Does it save tokens?

It should, but there is no fixed percentage. Claude works in fewer, better-chosen steps instead of finding the order by trial. One Smart optimise call stands in for a dozen separate ones. Replies are compact: about a fifth fewer characters than an indented reply, measured on a list of 40 parts. The main playbook is about 2,800 tokens, read once; the help articles cost nothing until Claude searches for one, and a search returns short snippets, not whole articles.

What leaves the computer

The app talks to Claude only through a small server on your own computer. Your model file is not sent anywhere. Claude gets back what its requests return: part names, counts, sizes, and the pictures it asks for, such as a screenshot of the viewport. Those pass through Claude the way anything you type to it does. Exports and turntable videos are saved in the app’s exports folder.

Claude mode (alpha)

If you would rather follow Claude than look at the app, Claude mode hides the app and shows what Claude does as a feed, with the model beside it. It is an early version: see Claude mode.

If it does not connect

• Claude says the app is not listening: the app is not open in a browser, or Let Claude connect is off. Open the app and switch it on.
• The top bar pill is missing: switch Let Claude connect on in Settings, or turn on Show the Claude pill in the top bar.
• The pill says another window took over: the app was opened in a second window and switched it on there. Switch it on again in the window you want.
• A request says it was turned off in Settings: set the matching one of the four kinds of change to Allow or Ask first.
• A long job such as Fit to budget on a large model can take minutes. Keep the app open and in front.
• The Claude section is missing from Settings: update the app. The connection is part of version 0.22.0 and later.
• Stuck or odd after an update: in Settings, Claude, Reconnect starts the connection from scratch (the small refresh button in the badge’s dropdown does the same). Restart the server… stops and starts the app’s server; open scenes stay and the connection comes back by itself.