las to obj conversion is related to the export of special topography models in LIDAR exchange format (LAS) to simple 3D OBJ format (Wavefront). This is probably doable, but due to the different nature and purpose of both files, the result might be very poor and simple compared to the original, but often enough for 3D printing purposes (printable 3D meshes).
This should be possible directly with CloudCompare or similar solution. A solution proposed often in various community forums is to use VRML/STL format as alternatives; both can be exported to OBJ with ease.
A viable route is to export LiDAR LAS files to TIN format using the LAStools and then export the .tin file to OBJ or STL. It all depends on the available software choices.
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