3D EM Field Volume: Flying a Probe Through Real Interference

This 3D companion to the flat field-strength map renders the same superposed electromagnetic field as a volumetric glow: a grid of sample points floating above the ground, colored and scaled by total field strength from a power line (1/r, line-source falloff), a cell tower and a parked vehicle (both 1/r², point-source falloff). Drag inside the scene to fly a probe sphere directly through the glowing volume — the meter readout updates continuously and always attributes most of the reading to whichever real source the probe is nearest, never spreading evenly through space the way a genuinely unexplained field would have to. Toggle probe-flying off to orbit the camera and inspect the field cloud from any angle.