Interactive 3D black hole lab explaining gravitational lensing

Prompt

I asked Opus 5.5 to explain gravitational lensing by building an interactive black hole lab

One prompt for the first version, then a dynamic workflow to polish it for three rounds while I slept. This is what I woke up to: 5h 28m end to end, $90 at API prices

https://blackhole.voxyz.ai

Drag the black hole and the sky behind it bends into arcs, closing into a full ring when everything lines up

Each round ran 3 agents. Two reviewers each picked 9 to 10 issues and ranked them P0, P1, P2. The third one fixed them.
Round 1: 3D materials and lighting + UI and type
Round 2: camera motion and interaction + science-communication design
Round 3: a design director deciding whether it ships + visual QA and performance

Every P0 got fixed, the rest only if worth it. When the two reviewers disagreed, it picked one and wrote down why. It backed up before each round, checked screenshots after, and rolled back anything it couldn't fix.