The badge, measured
The badge from bike.js on a piece of the down tube, seen from the side. The dark disc with the orange "L" sits on the tube, tilted with it. 128 triangles: the tube's 96 plus the badge's 32.
The showroom gets its last part, the Lumen badge, then goes through a launch check: a budget, a priced part list, a text alternative, a fallback picture, named buttons. The same checks live on as the project's own tests, and a README records what you measured, for your portfolio.
Change the code and press Run (Ctrl+Enter). Predict what will happen first, then break it on purpose and read what changes. Your edits are saved and match the lesson page.
Ready for more? This phase has 4 hands-on exercises with automatic checks.
Practice questions
Write the code in the editor, run it, then open the model answer to compare.
Add a test that fails if any part's material is transparent but has no alphaTest, which can cause sorting problems (transparent, Topic 5.1).
The launch check shows 48 of 50 geometries. Before a 20th part, how do you make room without raising the limit?
Explain it without notes
Walk an interviewer through your showroom in two minutes: what it does, how it loads, what you measured, and what you would do next.
Which of the launch checks belong in unit tests, which need a real browser, and which need a person?
Why does the badge use a CanvasTexture instead of an image file, and what does that cost?
Console
Nothing logged yet.Expected console output
turned 40.4 degrees; the tube climbs at 40.4
off the centre line: 0.3 mm; in front of the tube's surface: 3 mm
triangles: 128, draw calls: 2