explainer · v3
How code becomes a video
A marble rolls through thirteen stages, and none of it was ever filmed. This is how a program turned it into a video, step by step, and where the 38 minutes went.
6:45 · 2560×1440 · narrated · direct link to the MP4
Chapters
0:00 Intro: a video nobody filmed
0:39 1 · Physics: rules → a list of numbers
1:35 2 · The camera: just more numbers
2:08 3 · Rendering: colouring 3.4 billion dots
2:59 CPU or GPU? The painters
3:46 4 · Encoding: keep only what changed
4:26 5 · Sound from the collision list
4:51 6 · Muxing: one file, two tracks
5:05 Where the 38 minutes went
5:20 Making it faster
6:02 Realistic light: where it gets hard
6:34 Ending
Earlier versions
v2 of this explainer 10 min · 1080p
The Marble Machine the 55-second video this explainer is about
Voice: ElevenLabs v3 “Chris”. Every number on screen comes from the real project: the simulation, the camera file, the frames and the H.264 file. Estimates are marked as estimates.