shadowtor/fusion-studio

What does fusion-studio do?

You model in Fusion by sending Python scripts to its MCP server. The user supplies photos, measurements and taste. You build the model, look at it, and fix it.

0. Connect (always first)

python <skill>/scripts/fusion_mcp.py ping

Prints the Fusion version and the open document. If the fusion_mcp_* MCP tools are loaded use those (fusion_mcp_execute with featureType: "script", fusion_mcp_read for screenshots and API docs, fusion_mcp_update for undo). Otherwise the client does the same from a shell. If ping cannot connect, tell the user to start Fusion and enable its MCP server. Do not guess.

Rules that protect the user's work:

• Never edit a document that was already open. new_design() in fx_lib.py opens a fresh one. Read open documents only with --ro.
• Never save, close or overwrite unless asked. Exports go in the project folder.
• Do not wrap run() in try/except. A raised error is how you learn what failed.
• Scripts cannot modify while a command dialog is open. Ask the user to close it, or use --ro to inspect.

1. Pick the mode (the selector)

Ask with one question, recommending Print unless the brief says otherwise. Do not start modelling before this is answered.

Mode	For	Built as	Finish
Print	Parts printed on the user's printer: holders, brackets, enclosures, keychains	Fit tolerances, wall rules, orientation, one component per printed part	3MF per part + STEP
Showcase	Items that are shown, not printed: acrylic keychains for a crowdfunding page, exploded views for video	Look first: layered parts, thickness of real materials, exploded layout	PNG on transparent background, OBJ, STEP
Apparel	Clothing brand mockups: hang tags, labels, trims, buttons, zip pulls, packaging, display pieces	Flat artwork on 3D trims, real material thickness	PNG views, STEP, artwork placement notes

Details: references/modes.md. For Print, also ask the filament (PLA, PETG, ABS, ASA, TPU, nylon, PC, or a carbon-filled version) and use the Bambu Lab H2C unless told otherwise. The filament sets the fits and the limits for wall thickness, overhang angle and bridge length: references/materials.md, references/print-rules.md.

Then run python <skill>/scripts/new_project.py <name> --mode print|showcase|apparel [--material PETG] to create the project folder (project.json, build/, shots/, exports/).

2. Brief and measurements

Ask for what you cannot invent: the real size of anything the model must fit (a can, a phone, a key), the material, the wall style, and reference photos. Say which numbers are assumed and put them in project.json under assumptions. A missing dimension becomes a named parameter with an obvious default, never a buried number.

3. Parameters first

Everything measurable becomes a user parameter with a comment, in three groups: measured (can diameter), fit (clearances, wall) and derived (expressions built from the others). In Print mode call print_profile("PETG") first: it creates the material's fit_press, fit_close, fit_free, min_wall, min_feature and hole_comp parameters, and the fits are diametral (total across both sides). Use them instead of inventing clearances. Names are 3+ characters with an underscore (can_dia): single letters such as w, h, t collide with unit names and Fusion refuses them. Sketch dimensions and extrude distances take the parameter expressions, so changing one number changes the model. Read references/fusion-api.md before writing the first script.

4. Build in small scripts

Prepend the helper library with --lib:

python <skill>/scripts/fusion_mcp.py run build/01_body.py --lib
python <skill>/scripts/fusion_mcp.py shot shots/01.png --dir iso-top-right

fx_lib.py gives you new_design, param, component, sketch, rect, circle, extrude, box, fillet, chamfer, edges_where, appearance, view, health, report, export, and for Print mode (fx_print.py) print_profile, print_check, fit_coupon. One component per physical part, named <Part> - PRINT or - SHOWCASE. Fillets go last. Look at every screenshot before moving on. If the picture and the numbers disagree, trust the picture and find the bug.

Unknown API? fusion_mcp.py api "ExtrudeFeatures" --filter adsk.fusion returns the live docs. Prefer that to memory.

5. Verify before saying done

1. health() reports 0 problems.
2. Parametric test: change the main measured parameter, check health() and report() again, set it back. A model that breaks here is not finished.
3. Screenshots from at least iso, front and one section or underside view, read by you.
4. Print mode: print_check("PETG") (thin walls and overhangs, long bridges, small or horizontal holes, bed fit), then the orientation, supports and first-layer edge stated. Fix every WARN or say why it is acceptable. For any fit that matters, run fit_coupon() first and print it: it takes minutes and sets the real clearance for this filament and printer.
5. Print mode: export the 3MF and run python <skill>/scripts/slicer_check.py exports/part.3mf --material PETG. It drives OrcaSlicer headless on the H2C profiles and reports watertight or not, print time, filament, whether supports are needed, and whether your orientation is the slicer's best. Feed the result back into the model. The GUI and the optional orcaslicer-mcp server are alternatives: references/slicer.md.
6. Say what is not proven. A model that looks right has not been test printed. Name the first test print and which parameter to tune after it.

6. Export and hand over

Print: export(body, path, "3mf") for each part, plus step. Showcase: transparent PNG per angle (shot uses a transparent background when asked), OBJ for video tools. Apparel: PNG views and STEP. Then give the user: files, parameter list, assumptions, the first test to run.

What this skill does not do

• It does not send jobs to the printer or choose temperatures and speeds. It slices only to check a model (support need, time, orientation) and states support choices as starting points.
• It does not replace a test print. Clearances are starting values for a 0.4 mm nozzle, not guarantees.
• It cannot see the user's photos unless they share them. Ask for dimensions rather than estimating from a picture.
• It does not model fabric. Apparel mode covers trims, labels, tags, hardware and packaging.