Call Clipper from Python script

Scripting
1

Is there a way of calling Clipper’s OffsetPolyline from a Python script, without using rs.Command()?
Thank you

2
3

I have this little script working:

from __future__ import print_function
import rhinoscriptsyntax as rs
import ghpythonlib.components as ghcomp

def main():
    msg = 'Pick polyline'
    pline = rs.GetObject(msg, filter=rs.filter.curve, preselect=True, select=True)
    if not pline:
        print("Error: Need polyline.")
        return

    ret = ghcomp.ClipperComponents.PolylineOffset(pline, distance=1, tolerance=0.001,
            plane=rs.WorldXYPlane(), closedfillet=1, openfillet=0, miter=2)
    if not ret:
        return
    print(ret)
    return

if __name__ == '__main__':
    main()

which runs without errors. It outputs this:

{‘contour’: <Rhino.Geometry.PolylineCurve object at 0x00000000000000BE [Rhino.Geometry.PolylineCurve]>, ‘holes’: <Rhino.Geometry.PolylineCurve object at 0x00000000000000BF [Rhino.Geometry.PolylineCurve]>}

I assume ‘contour’ is the outset, and ‘holes’ the insets???

To add the actual outset polyline to the document, would I have to run sc.doc.Objects.AddPolyline(???) somehow? How would I do this?

I also don’t see the Project=FitToCurve option that I get when running OffsetPolyline as a Rhino command.

Thank you for your patience

4

I assume ‘contour’ is the outset, and ‘holes’ the insets???

Correct!

To add the actual outset polyline to the document, would I have to run sc.doc.Objects.AddPolyline(???) somehow? How would I do this?

This is the first time I’m using RhinoPython and node in code, but what you get back from the node in code is quite ackward. It can be a list, or it can be a single item, but it changes its type on the quantity of items. :confounded:

I also don’t see the Project=FitToCurve option that I get when running OffsetPolyline as a Rhino command.

This is a bit different in the grasshopper component. Fitting a plane to the points of the first polyline is what it actually does.

from __future__ import print_function
from collections import Iterable
import rhinoscriptsyntax as rs
import ghpythonlib.components as ghcomp
import scriptcontext


def main():
    msg = 'Pick polyline'
    #pline = rs.GetObject(msg, filter=rs.filter.curve, preselect=True, select=True)
    plines = rs.GetObjects(msg, filter=rs.filter.curve, preselect=True, select=True)
    if not plines:
        print("Error: Need polyline.")
        return

    # Equivalent to fit plane:
    points = rs.PolylineVertices(plines[0])
    plane = rs.PlaneFitFromPoints(points)
    
    ret = ghcomp.ClipperComponents.PolylineOffset(plines, distance=100, tolerance=0.001,
            plane=plane, closedfillet=1, openfillet=0, miter=2)

    if (ret.contour):
        if isinstance(ret.contour, Iterable):
            for item in ret.contour:
                scriptcontext.doc.Objects.AddCurve(item)
        else:
            scriptcontext.doc.Objects.AddCurve(ret.contour)
    
    if (ret.holes):
        if isinstance(ret.holes, Iterable):
            for item in ret.holes:
                scriptcontext.doc.Objects.AddCurve(item)
        else:
            scriptcontext.doc.Objects.AddCurve(ret.holes)
    return

if __name__ == '__main__':
    main()
5

Ah, I see. Thank you so much for explaining how this works