OpenSCAD User Manual/STL Import

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import[edit]

Imports a file for use in the current OpenSCAD model

Parameters

<file> 
A string containing the path to the STL or DXF file.
<convexity> 
An Integer. The convexity parameter specifies the maximum number of front sides (back sides) a ray intersecting the object might penetrate. This parameter is only needed for correctly displaying the object in OpenCSG preview mode and has no effect on the polyhedron rendering.

Usage examples:

import("example012.stl", convexity=3);


Convexity[edit]

Openscad convexity.jpg

This image shows a 2D shape with a convexity of 4, as the ray indicated in red crosses the 2D shape a maximum of 4 times. The convexity of a 3D shape would be determined in a similar way. Setting it to 10 should work fine for most cases.

Notes[edit]

In the latest version of OpenSCAD, import() is now used for importing both 2D (DXF for extrusion) and 3D (STL) files.


If you want to render the imported STL file later, you have to make sure that the STL file is "clean". This means that the mesh has to be manifold and should not contain holes nor self-intersections. If the STL is not clean, you might get errors like:


 CGAL error in CGAL_Build_PolySet: CGAL ERROR: assertion violation!
 Expr: check_protocoll == 0
 File: /home/don/openscad_deps/mxe/usr/i686-pc-mingw32/include/CGAL/Polyhedron_incremental_builder_3.h
 Line: 199

or

 CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation!
 Expr: pe_prev->is_border() || !internal::Plane_constructor<Plane>::get_plane(pe_prev->facet(),pe_prev->facet()->plane()).is_degenerate()
 File: /home/don/openscad_deps/mxe/usr/i686-pc-mingw32/include/CGAL/Nef_3/polyhedron_3_to_nef_3.h
 Line: 253

In order to clean the STL file, you have the following options:

- use http://wiki.netfabb.com/Semi-Automatic_Repair_Options . This will repair the holes but not the self-intersections.

- use netfabb basic. This free software doesnt have the option to close holes nor can it fix the self-intersections

- use MeshLab, This free software can fix all the issues


Using MeshLab, you can do:

- Render - Show non Manif Edges

- Render - Show non Manif Vertices

- if found, use Filters - Selection - Select non Manifold Edges or Select non Manifold Vertices - Apply - Close. Then click button 'Delete the current set of selected vertices...' or check http://www.youtube.com/watch?v=oDx0Tgy0UHo for an instruction video. The screen should show "0 non manifold edges", "0 non manifold vertices"


Next, you can click the icon 'Fill Hole', select all the holes and click Fill and then Accept. You might have to redo this action a few times.

Use File - Export Mesh to save the STL.

import_stl[edit]

<DEPRECATED.. Use the command import instead..>

Imports an STL file for use in the current OpenSCAD model

Parameters

<file> 
A string containing the path to the STL file to include.
<convexity> 
Integer. The convexity parameter specifies the maximum number of front sides (back sides) a ray intersecting the object might penetrate. This parameter is only needed for correctly displaying the object in OpenCSG preview mode and has no effect on the polyhedron rendering.

Usage examples:

import_stl("example012.stl", convexity = 5);