openscad-step-reader

A proof-of-concept project, testing OpenSCAD / STEP files loading.

Usage

$ openscad-step-reader

A proof-of-concept program for STEP/OpenSCAD integration

usage: openscad-step-reader [options] INPUT.STEP

Output is written to STDOUT.

options are:
   -h, --help         this help screen
   -V, --version      version information

   -o, --stl-occt     convert the input STEP file into ASCII STL file
                      using OpenCASCADE code. This should be the baseline
                      when debugging/troubleshooting incorrect outputs.

   -a, --stl-ascii    convert the input STEP file into custom ASCII STL file,
                      using our code. This is a good test to check mesh
                      triangulation code. EXCEPT for the 'normal' values
                      which are not produced, the vertex values should be
                      equivalent to those with --stl-occt.

   -s, --stl-scad     convert the input STEP file into SCAD code, containing
                      a single 'polyhedron' call with the STL triangles stored
                      in SCAD vectors.

   -f, --stl-faces    convert the input STEP file into SCAD code, retaining the
                      'face' information from the STEP file. Each face will be rendered
                      in a different color in openscad $preview mode.

   -e, --explore      Work-in-progress code, used for development and exploration
                      of OpenCASCADE class hierarchy, e.g.
                      Shell->Face->Surface->Wire->Edge->Vertex.
                      produces debug messges and no useful output.

Examples

See the [examples] sub directory for STEP files and their STL/SCAD output.

e.g. the files in examples/box were created with:

openscad-step-reader --stl-ascii examples/box/box.stp > examples/box/box-ascii.stl
openscad-step-reader --stl-scad  examples/box/box.stp > examples/box/box.scad
openscad-step-reader --stl-faces examples/box/box.stp > examples/box/box-faces.scad

The --explore option is a development tool to help learn and understand the OpenCASCADE hierarchy class model (e.g. shape->shell->face->surface->wire->edge->vertex).

$ openscad-step-reader --explore example/cylinder/cyl.stp

Shell 0
  Face 0 Type = 1:Cylinder
    Wire 0
     edge 0
       VertexFirst 2, -4.89859e-16, 10
       VertexLast 2, -4.89859e-16, 10
     edge 1
       VertexFirst 2, -4.89859e-16, 0
       VertexLast 2, -4.89859e-16, 10
     edge 2
       VertexFirst 2, -4.89859e-16, 0
       VertexLast 2, -4.89859e-16, 0
     edge 3
       VertexFirst 2, -4.89859e-16, 0
       VertexLast 2, -4.89859e-16, 10
  Face 0 Type = 0:Plane
    Wire 0
     edge 0
       VertexFirst 2, -4.89859e-16, 10
       VertexLast 2, -4.89859e-16, 10
  Face 0 Type = 0:Plane
    Wire 0
     edge 0
       VertexFirst 2, -4.89859e-16, 0
       VertexLast 2, -4.89859e-16, 0

The --stl-scad converts to STEP to triangles (just like an STL file), then writes the triangles as openSCAD code:

$ openscad-step-reader --stl-scad example/box/box.stp
points = [
  [0,10,0],[0,0,0],[0,0,10], // Triangle 1 / 12
  [0,10,10],[0,10,0],[0,0,10],
  [10,0,10],[10,0,0],[10,10,0],
  [10,0,10],[10,10,0],[10,10,10],
  [0,0,0],[10,0,0],[10,0,10],
  [0,0,10],[0,0,0],[10,0,10],
  [10,10,10],[10,10,0],[0,10,0],
  [10,10,10],[0,10,0],[0,10,10],
  [0,0,0],[0,10,0],[10,10,0],
  [10,0,0],[0,0,0],[10,10,0], // Triangle 10 / 12
  [10,10,10],[0,10,10],[0,0,10],
  [10,10,10],[0,0,10],[10,0,10],
];
faces = [
  [0,1,2], // Triangle 1 / 12
  [3,4,5],
  [6,7,8],
  [9,10,11],
  [12,13,14],
  [15,16,17],
  [18,19,20],
  [21,22,23],
  [24,25,26],
  [27,28,29], // Triangle 10 / 12
  [30,31,32],
  [33,34,35],
];
module solid_object() {
  polyhedron (points,faces);
}

solid_object();

License

Written by Assaf Gordon ([email protected]) License: LGPLv2.1 or later