Teardown simulator
One machine, one offline HTML page: a code-built model in real units, one solver as pure functions of one input, live panels, a button per subsystem, an auto tour, a critic pass, a recorded 60 fps film with a scored soundtrack, and an optional publish step.
Rules
- Reference first. Before building, ask for or find a cutaway, photo or clip. No reference, no build.
- Never invent numbers silently. Every number is sourced or flagged as an estimate, with where it came from.
- Confirm scope first. Heavy builds use a lot of Claude Code usage: agree on machine, beats, film or no film.
- Publishing needs an explicit yes, every time.
- On the host: user-level only, no sudo, leave cluster services alone, long renders in tmux with logs.
Pick a good machine
One moving input (crank angle, stroke 0..1, wind, time) and real published numbers. Good starters: bicycle derailleur, watch escapement (4 Hz), car differential, sewing-machine lockstitch, excavator arm. Avoid machines with many independent inputs or secret dimensions.
Simulator anatomy
- Machine — built from code in real units. 2. Model — one solver, pure functions of one input. 3. Panels — live charts from the same model. 4. Buttons — isolate/cut/show-alone per subsystem, views, sliders. 5. Window — the floor/stage shows what the solver says. 6. Tour — auto cursor tour; any input hands control; 25 s quiet hands it back.
Install and run (on )
npx skills add elvarofficial/teardown -g -a claude-code
cd ~/.claude/skills/teardown && npm install && npx playwright install chromium
# needs Node >= 20, ffmpeg, python3
mkdir -p ~/3d-studio/{projects,out,logs,smoke}
cd ~/3d-studio/projects/<machine>
tmux new -s <machine> 'claude 2>&1 | tee ~/3d-studio/logs/<machine>.log'
# inside Claude Code: /teardown ... (never --dangerously-skip-permissions)
Smoke test: node ~/.claude/skills/teardown/sims/build.mjs cessna-live and open the HTML from teardown-out/dist/.
Workflow (swap the [brackets])
- Brief: fill templates/brief.md (reference, single input, real numbers, parts) and confirm scope.
1. Build
/teardown Build [the Cessna 337 main landing gear] as an interactive 3D simulator. Reference attached: [a cutaway drawing of the gear]. Build it from code in real units: [parts]. Before you draw anything, write the model as pure functions of one input: [stroke from 0 to 1]. Use the real numbers: [rack travels 201 mm, pinion 32 teeth at module 4 mm, legs turn exactly 180°]. Check them by hand and show me the check. If you are not sure a number is real, say so and tell me where it comes from. Every part, every panel and every label reads from that one model. Nothing is animated by hand.
2. Console
Lay out a console around the machine at 1600×900: the title and the main live number top left, big: [engine speed in rpm]. Live charts that move with the machine: [valve lift over 720° of crank, PV loop]. A schematic panel that redraws the mechanism in 2D from the same model. One button per subsystem: isolate, cut, show alone. Camera views as buttons: [hero, front, side, top, inside]. Callouts with thin leader lines. Every panel redraws from the frame's state. No number on screen is typed in.
3. Look
Style: a clean study model on a pale studio. Light background, soft shadows on an invisible floor, one accent colour for the part working now: [accent colour]. The machine fills 60–70% of the view. Dark parts glossy, liners glass, metal roughness at least 0.45. Near-white parts get a thin ink outline or a darker ground. Pick the camera for the mechanism: [3/4 view] if face-on collapses into a lattice.
4. Critic
Before you show me anything: 1. Render a still at every beat of the tour and read each one for: a part passing through another, a part floating off its mount, a label covering what it names, a number disagreeing with the pose. 2. Scrub every transition at 0.2 s steps for jumps. 3. Fix collisions with a number in the parameter block, never hide them with the camera. Tell me what you checked and what you fixed. Show me the stills.
5. Drive
The tour plays by itself with a cursor pressing the buttons: [tour beats]. Any click, drag, scroll or key hands control to the visitor; 25 s of quiet hands it back. Drag to orbit, scroll to zoom, [key] hides the panels. Warm every shader before the first frame. Test on an integrated GPU with quality steps: no AO, lower pixel ratio, smaller shadows, panels every other frame.
6. Record
Make render(t) a pure function of time over [20 s]. Draw every frame at 60 fps, 1920×1080 in headless Chrome, and pipe it to ffmpeg as H.264 yuv420p with faststart. Give me a contact sheet of every beat.
7. Score
Score it in code on the same timeline: [Am9 chords at 92 bpm, a thump on each power stroke, a click per button press, rising air under the throttle drag]. Master to -14 LUFS, true peak under -1 dB, and mux it into the video.
8. Publish
Get the HTML under 1 MB (large models go in sibling files). Make a 1200×630 preview card from the best frame, with absolute image URLs. Deploy to [Vercel / host] only after I say yes.
9. Break it (bonus)
Add one slider for [wind 0–15 m/s] and run the model live with it; show the effect on the same panels.
Lessons
- Keep the page under 1 MB: a 15.9 MB page killed the X link card; 967 KB fixed it.
- Integrated GPUs: quality steps (no AO, lower pixel ratio, smaller shadows, panels every other frame) took one build from 15 fps to 75 fps.
- Stills catch collisions that motion hides. Always run the critic pass.
- Fix collisions in the parameter block, never with the camera.
Deliverable
Folder with: <machine>.html (offline, <1 MB), critic report (templates/critic-report.md) with stills, contact sheet, <machine>.mp4 (60 fps, -14 LUFS), the model's hand-check of numbers with sources/flags, and a preview card if publishing.
Credits
Workflow and prompts from Elvar (@elvar_official), "How I Turn Any Machine Into a 3D Simulator You Can Take Apart" (X, 2026-10-30). Runs Elvar's teardown skill, github.com/elvarofficial/teardown (MIT), built on whaleyxbt/claude-motion (MIT).