Your last example is a standard laser triangulation rig. They're extremely simple to build and give excellent accuracy. Here's an example system I was involved

Your last example is a standard laser triangulation rig. They're extremely simple to build and give excellent accuracy. Here's an example system I was involved with for cast steel: https://doi.org/10.1109/CRV.2016.55 https://doi.org/10.1109/CRV.2016.55 The pedant in me wants to point out that laser triangulation has nothing to do with LIDAR, even though it's commonly lumped in. It's basically a parallax measurement, whereas LIDAR refers explicitly to time of flight (either direct or by proxy from phase/frequency offset). Mostly they're used for profiling on conveyor-based systems - anything where the target moves underneath the stripe. The downside is usually a big trade off with accuracy and depth of field; and usually their usable range is poor (> 5m and you're struggling and have eye safety problems). You can buy nm-precision systems, but they only work within a range of a few cm. Also the triangulation angle is important - the further away you go, the wider your laser-camera baseline needs to be to retain accuracy.