PLAXIS 3D allows importing points, lines/polycurves, surfaces and volumes, next to point cloud import. You can also import surface as the top and bottom soil surfaces of your borehole, in the Modify Soil Layers configuration window in the Surfaces tab. When importing a geometry file, a list of possible file extensions are shown.
With the internal changes for the geometric data model for PLAXIS 3D 2016, Plaxis will no longer support the import of triangulated geometry. This includes *.3ds, *.stl, *.dwg and triangulated *.dxf files. For supported types of older PLAXIS versions, see the attached document.
Converting triangulated surfaces in a CAD software for efficient modelling in PLAXIS 3D
Importing CAD data into PLAXIS 3D
PLAXIS 3D 2016: Fully parametric geometry
[Tips and Tricks]
Can I reuse existing PLAXIS 3D geometrical objects in a new project?
Modelling a tapered pile