GradientStats (shader)

Measured gradient statistics for one field (§RQ-IM-6 R1).

In the namespace shader. Declared in src/libs/libshader/shader/FieldProbe.hpp.

Detailed description

The quantity that matters to a sphere tracer is the Lipschitz constant L = sup‖∇Φ‖: the field may be stepped along at most 1/L of what it reports before the step can overshoot the surface. A field with L > 1 is not a distance field, it is an OVERESTIMATE, and every tracer remedy in §RQ-2 is downstream of that.