X-rays travel through the object at angle φ. Each of the detector pixels records the integrated intensity along its ray — a line integral through the object.
Collecting such projections over 96 angles from 0° to 180° builds the sinogram. Each point source in the object traces a sinusoidal arc in the sinogram — hence the name.
The projector uses the pixel-driven anterpolation method: each pixel contributes to nearby detector bins via a tent (hat) weight proportional to the overlap.