We will discuss some physical limits of 3D-sensors that work on ''rough'' surfaces. An important result is that the most frequently used principles (laser triangulation and focus sensing with projected light spots) cannot achieve a better depth resolution than given by the Rayleigh depth of field. However we can achieve ''superresolution'' in depth by sacrificing lateral resolution: There is an ''uncertainty relation'' between lateral and longitudinal resolution. 1 .
Gerd Haeusler, Gerd Haeusler,
"Fundamental limits of three-dimensional sensing (or: nature makes no presents)", Proc. SPIE 1319, Optics in Complex Systems, (1 July 1990); doi: 10.1117/12.34739; https://doi.org/10.1117/12.34739