Case file 004AR textbooks
The problem
“Our books are printed once. We want every page to keep teaching after it’s printed.”
Solved
- For
- A school textbook series
- Built
- AR textbook platform: web app, admin panel, scan + 3D pipeline
- Stack
- Next.js · Express · Postgres + pgvector · S3 · AI image-to-3D
- Result
- Number to confirm
01 · The pain
Ink can’t be updated.
- A new quiz means a new print run.
- A mistake on page 12 stays on page 12 for years.
- The teacher’s answers end up in the students’ bags.
02 · The fix
The code stays printed. What it opens keeps changing.
Play the admin: switch content on and off for page 12 and watch what a scan opens. The printed code never changes, and nothing gets reprinted.
English Reader · page 12
L is for Lion
Admin · page 12
What a scan opens
L is for Lion
Quiz
Which word starts with L?
3D model
Lion · spin it, or view it in your room
No code? Point the camera at the picture.
Match: Lion page. Opening it.
03 · How it works
Three pieces, and a phone that couldn’t remember 500 pictures.
One code per page, not per file
Each printed QR is a normal web link that stands for a page: series, book, class, page number. Any phone camera can open it, no app needed.
An admin panel decides what’s behind it
Quizzes, colouring sheets, media and 3D models are added, edited or retired per page, in bulk. Teacher guides sit behind a PIN, so students never need accounts.
A 3D model for every letter
Models for the English Reader, A for Ant to Z for Zip, were generated from photos by an image-to-3D AI and stored with the page they belong to.
The hard part
Recognising a page without a code.
The usual way is to load every picture’s tracking data onto the phone. The library’s own issue tracker shows six pictures already reaching 32 MB and crashing mid-range phones. The series is planned at around 500.
So the phone just sends a photo. The server turns it into a vector, finds the closest page picture in Postgres, and only answers if it’s close enough. A blurry photo gets “try again”, not a wrong lion.
6 pictures → 32 MB on the phone
1 photo → sent to the server, matched there
Figures from the image-tracking library’s issue tracker (mind-ar-js #22).
04 · What changed
Every page can change without a single reprint.
- Pages with a live code
- —
- Scans
- —
- Schools using it
- —
Metric to confirm · across the series
Metric to confirm · students and teachers
Metric to confirm · licensed schools