docs(prompting): coil carries the wire stroke, anchors to the diving wire, world turns

docs/prompting/runtimes-and-3d.mdx

@@ -92,7 +92,7 @@ The rule of thumb: anything the video needs to *know* must be present before ren
 
 This is the clause in the [full capstone prompt](/prompting/capstone#the-full-prompt-verbatim) that buys the piece — prompt language you can lift for your own video:
 
-> **Depth (52–56s).** The wire spirals off the flat plane into real 3D — a **Three.js scene via the frame adapter** (never CSS fake-3D): the camera descends following the wire as it coils around a rim-lit faceted form (ink material on charcoal), mono axis readouts landing on cue, then rises back to the plane with the wire leading the way out. The coil winds up out of the wire and collapses back onto it — its ends never float cut off in mid-air — and the protagonist chip joins the 3D scene for the crossing: it rides the coil ITSELF, looping around the form with the wire and passing behind it under true depth occlusion — never cutting straight past on a flat plane, never floating over the geometry as an overlay. Stand the internal camera far enough back that all three turns read as a coil in space, and light the tube so its near and far sides shade differently; a flat-shaded tube seen side-on reads as a 2D sine wave, not a helix.
+> **Depth (52–56s).** The wire spirals off the flat plane into real 3D — a **Three.js scene via the frame adapter** (never CSS fake-3D): the camera descends following the wire as it coils around a rim-lit faceted form (ink material on charcoal), mono axis readouts landing on cue, then rises back to the plane with the wire leading the way out. The coil winds up out of the wire and collapses back onto it — its ends never float cut off in mid-air — and the protagonist chip joins the 3D scene for the crossing: it rides the coil ITSELF, looping around the form with the wire and passing behind it under true depth occlusion — never cutting straight past on a flat plane, never floating over the geometry as an overlay. Stand the internal camera far enough back that all three turns read as a coil in space, and light the tube so its near and far sides shade differently; a flat-shaded tube seen side-on reads as a 2D sine wave, not a helix. **The coil is the SAME wire, so it must carry the same 3px stroke — a fat pipe wrapped around the form reads as a second, unrelated object — and its axis must sit exactly on the wire's own height here (the wire dives into this region; anchor to where the line actually is, not where it runs elsewhere).** Turn the whole 3D world slowly about that axis while the camera is present: rotating about the axis is what sells the depth without lifting the coil off the line.
 
 <video controls muted loop playsinline preload="metadata" src="https://static.heygen.ai/hyperframes-oss/docs/images/prompting/capstone-region-depth.mp4" style={{ borderRadius: "0.5rem", marginTop: "0.75rem" }}></video>
 *That clause, rendered — the region cut from the finished film.*