Various 3D graphics polygon files (.ply) can typically be exported to another common 3D objects format (.obj) so they can be used in most of the 3D modeling software. This will only work with valid PLY files that contain 3D objects data as is pretty much the only ply to obj conversion that makes sense.
Open PLY file Open OBJ fileA Mac version of the popular 3D visualisation software
A converter for 3D formats
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