OpenSCAD User Manual/Importing Geometry

import() module: Importing Geometry This section is about the module that imports geometry. For the function that imports and returns data, see import() function: Importing data. Importing geometry is achieved by the import() command. 2015.03-2 The File >> Open command may be used to insert this command. The file type filter of the Open File dialog may show only OpenSCAD files, but file name can be replaced with a wildcard (e.g. *.stl) to browse to additional file types. 3D geometry formats STL (both ASCII and Binary) OFF OBJ AMF (deprecated) 3MF 2D geometry formats DXF PDF SVG Data formats JSON Development snapshot Other CSG can be imported using include<> or loaded like an SCAD file PNG can be imported using surface() Parameters <file> A string containing the path to file. If the given path is not absolute, it is resolved relative to the importing script. Note that when using include<> with a script that uses import(), this is relative to the script doing the include<>. <center> Boolean. If true, the center of the object is placed at the origin. Development snapshot <convexity> An Integer. The convexity parameter specifies the maximum number of front sides (or back sides) a ray intersecting the object might penetrate. This parameter is needed only for correctly displaying the object in OpenCSG preview mode and has no effect on the polyhedron rendering. Optional. <id> String. For SVG import only, the id of an element or group to import. Optional. Elements in an SVG can have both an ID and a Label, and the label will not work here. In your vector editing program, examine the object's properties to find (or assign) the ID. Development snapshot <layer> For DXF and SVG import only, specify a specific layer to import. Optional. $fn Double. The number of polygon segments to use when converting circles, arcs, and curves to polygons. Development snapshot $fa Double. The minimum angle step to use when converting circles and arcs to polygons. Development snapshot $fs Double. The minimum segment length to use when converting circles and arcs to polygons. Development snapshot: import("example012.stl", convexity=3); import("D:/Documents and Settings/User/My Documents/Gear.stl", convexity=3); (Windows users must "escape" the backslashes by writing them doubled, or replace the backslashes with forward slashes.) data = import("data.json"); // for data formats the file content is assigned to a variable Read a layer of a 2D DXF file and create a 3D shape. linear_extrude(height = 5, center = true, convexity = 10) import_dxf(file = "example009.dxf", layer = "plate"); Convexity 400px| This image shows a 2D shape with a convexity of 2, as the ray indicated in red intersects with the 2D shape in at most two sections. The convexity of a 3D shape would be determined in a similar way. Setting it to 10 should work fine for most cases. Notes In the latest version of OpenSCAD, import() is now used for importing both 2D (DXF for extrusion) and 3D (STL) files. CGAL ERROR: assertion violation! 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, it might initially import and preview fine, but then as soon as you attempt to perform computational geometry on it by rendering a combination of it with something else, you might get warnings about it not being manifold, your imported stl might disappear from the output entirely, or 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 to repair the holes but not the self-intersections. use netfabb basic. This free software doesn't 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. If Meshlab can't fill the last hole then Blender might help: Start Blender `X, 1` to remove the default object File, Import, Stl `Tab` to edit the mesh `A` to de-select all vertices `Alt+Ctrl+Shift+M` to select all non-manifold vertices `MMB` to rotate, `Shift+MMB` to pan, `wheel` to zoom `C` for "circle" select, `Esc` to finish `Alt+M, 1` to merge or `Space` and search for "merge" as alternative Merging vertices is a useful way of filling holes where the vertices are so closely packed that the slight change in geometry is unimportant compared to the precision of a typical 3D printer import_dxf import_dxf() import() Read a DXF file and create a 3D shape. linear_extrude(height = 5, center = true, convexity = 10) import_dxf(file = "example009.dxf", layer = "plate"); import_stl import_stl() import() (see above) Imports an STL file for use in the current OpenSCAD model import_stl("body.stl", convexity = 5); import() function: Importing data This section is about the function that imports and returns data. For the module that imports geometry, see import() module: Importing Geometry. Development snapshot Note: requires enabling the experimental import-function feature. Imports an external data file and returns its contents as a data value. Only JSON files are supported; other file types may be added in the future. Normally, the type of data to be imported is inferred from the file extension. If necessary, the type can be explicitly specified with the type parameter. Extension Type Notes .json json A single JSON value is imported Parameters file String. The path to the file to be imported. type String, optional. The type of data to be imported. By default, the file type is inferred from the file extension. JSON A single JSON data value, typically an object or arrray, is imported and returned. WARNING: The remainder of the file is ignored; in the future additional text after the data value may yield an error. JSON type OpenSCAD type Array List Object Object Number Number String String Boolean Boolean null undef Importing this file: {"people":[{"name":"Helen", "age":19}, {"name":"Chris", "age":32}]} with this OpenSCAD call: val = import("mydata.json"); // or, if the file doesn't have a ".json" extension, // val = import("mydata", type="json"); // val = import("mydata.cfg", type="json"); echo(val); yields this OpenSCAD object: { people = [{ age = 19; name = "Helen"; }, { age = 32; name = "Chris"; }]; } Errata An earlier version of this document erroneously said that this function could import .csv files. That was never true; it has never been able to correctly import a non-trivial CSV file. It attempted to import all file types as JSON. If you tried to import a CSV file that happened to start with a number, it would import that one number, ignoring the rest of the file. surface surface() reads Heightmap information from text or image files. It can read PNG files. Parameters file String. The path to the file containing the heightmap data. center Boolean. This determines the positioning of the generated object. If true, object is centered in X- and Y-axis. Otherwise, the object is placed in the positive quadrant. Defaults to false. invert Boolean. Inverts how the color values of imported images are translated into height values. This has no effect when importing text data files. Defaults to false. 2015.03 convexity Integer. The convexity parameter specifies the maximum number of front sides (back sides) a ray intersecting the object might penetrate. This parameter is needed only for correct display of the object in OpenCSG preview mode and has no effect on the final rendering. Text file format The format for text based height maps is a matrix of numbers that represent the height for a specific point. Rows are mapped to the Y-axis, columns to the X axis. The numbers must be separated by spaces or tabs. Empty lines and lines starting with a # character are ignored. Images 2015.03 Currently only PNG images are supported. Alpha channel information of the image is ignored and the height for the pixel is determined by converting the color value to Grayscale using the linear luminance for the sRGB color space (Y = 0.2126R + 0.7152G + 0.0722B). The gray scale values are scaled to be in the range 0 to 100. Examples Example 1: //surface.scad surface(file = "surface.dat", center = true, convexity = 5); %translate([0,0,5])cube([10,10,10], center =true); #surface.dat 10 9 8 7 6 5 5 5 5 5 9 8 7 6 6 4 3 2 1 0 8 7 6 6 4 3 2 1 0 0 7 6 6 4 3 2 1 0 0 0 6 6 4 3 2 1 1 0 0 0 6 6 3 2 1 1 1 0 0 0 6 6 2 1 1 1 1 0 0 0 6 6 1 0 0 0 0 0 0 0 3 1 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 Result: File:Openscad_surface_example_x1.png Example 2 // example010.dat generated using octave: // d = (sin(1:0.2:10)' * cos(1:0.2:10)) * 10; // save("example010.dat", "d"); intersection() { surface(file = "example010.dat", center = true, convexity = 5); rotate(45, [0, 0, 1]) surface(file = "example010.dat", center = true, convexity = 5); } File:Openscad surface example x2.png Example 3: 2015.03 // Example 3a scale([1, 1, 0.1]) surface(file = "smiley.png", center = true); // Example 3b scale([1, 1, 0.1]) surface(file = "smiley.png", center = true, invert = true); center 220 Example 3: Using surface() with a PNG image as heightmap input. OpenSCAD surface example input image.png Input image Input image OpenSCAD surface example.png Surface output Example 3a: surface(invert = false) OpenSCAD surface example (inverted).png Surface output inverted Example 3b: surface(invert = true)