🧫 TB Contact Tracing Investigation Simulator — 3D
A genuine WebGL/Three.js companion to the 2D contact-tracing simulator: the same concentric-circle ("stone in the pond") exposure model — household, frequent and casual contacts — rendered as real spherical exposure shells in 3D space, with the identical secondary-LTBI-rate, evaluation-count and new-active-case math driving every stage.
Why render contact-tracing rings in 3D
The classic "stone in the pond" model of TB contact investigation ranks contacts by exposure intensity, ripple by ripple: household and other high-exposure contacts first, then frequent contacts, then casual and community contacts only if transmission evidence justifies the expansion. This 3D companion keeps the exact model of the 2D original — the same baseline secondary-LTBI rates by infectiousness grade (12% smear-negative, 28% smear-positive, 46% cavitary disease), the same needing-evaluation and new-active-case counts, and the same expand-vs-close-contacts-only scope rule — but places the three exposure rings as real concentric spherical shells around the index case using a golden-spiral point distribution, so the geometry of "inner ring = higher priority" is visible from any angle instead of flattened onto one plane.
As the investigation-stage slider advances, ring shells fade in, contacts on each shell individually reveal a test outcome — negative, latent (LTBI) or new active disease — at the same rate the underlying math assigns them, and latent contacts draw a dashed line back to a floating treatment-linkage panel once the outcome stage is reached, exactly mirroring the treatment-cascade logic of the 2D canvas version. Drag to orbit the exposure shells, scroll or pinch to zoom, and use the same infectiousness and contact-count controls as the 2D version to see how each reshapes the ring populations and outcome counts in real time.