Methods, devices and systems of an optical sensor for spatially smart 3-D object measurements using variable focal length lenses to target both specular and diffuse objects by matching transverse dimensions of the sampling optical beam to the transverse size of the flat target for given axial target distance for instantaneous spatial mapping of flat target, zone. The sensor allows volumetric data compressed remote sensing of object transverse dimensions including cross-sectional size, motion transverse displacement, inter-objects transverse gap distance, 3-D animation data acquisition, laser-based 3-D machining, and 3-D inspection and testing. An embodiment provides a 2-D optical display using 2-D laser scanning and 3-D beamforming optics engaged with sensor optics to measure distance of display screen from the laser source and scanning optics by adjusting its focus to produce the smallest focused beam spot on the display screen. With known screen distance, the angular scan range for the scan mirrors can be computed to generate the number of scanned spots in the 2-D display.