topic Python script to create a chain of lines in Fusion API and Scripts Forum

Python script to create a chain of lines

cadTPLWJ — Sun, 05 Nov 2017 22:36:25 GMT

Code below is a script example.

Suppose I want lines between the points instead of the spline line, how would I do that?

Do I have to individually name all the little lines or can I make some kind of line collection?

import adsk.core, adsk.fusion, traceback

def run(context):
    ui = None
    try: 
        app = adsk.core.Application.get()
        ui = app.userInterface

        doc = app.documents.add(adsk.core.DocumentTypes.FusionDesignDocumentType)
        design = app.activeProduct

        # Get the root component of the active design.
        rootComp = design.rootComponent

        # Create a new sketch on the xy plane.
        sketch = rootComp.sketches.add(rootComp.xYConstructionPlane)

        # Create an object collection for the points.
        points = adsk.core.ObjectCollection.create()

        # Define the points the spline with fit through.
        points.add(adsk.core.Point3D.create(0, 0, 0))
        points.add(adsk.core.Point3D.create(5, 1, 0))
        points.add(adsk.core.Point3D.create(6, 4, 3))
        points.add(adsk.core.Point3D.create(7, 6, 6))
        points.add(adsk.core.Point3D.create(2, 3, 0))
        points.add(adsk.core.Point3D.create(0, 1, 0))

        # Create the spline.
        sketch.sketchCurves.sketchFittedSplines.add(points)
    except:
        if ui:
            ui.messageBox('Failed:\n{}'.format(traceback.format_exc()))

Re: Python script to create a chain of lines

Anonymous — Mon, 06 Nov 2017 08:35:31 GMT

Hello,

There is no API to create a chain of lines like what we create spline. However you should be able to create the lines one by one. Please refer to the codes as below:

import adsk.core, adsk.fusion, traceback

def run(context):
    ui = None
    try: 
        app = adsk.core.Application.get()
        ui = app.userInterface

        doc = app.documents.add(adsk.core.DocumentTypes.FusionDesignDocumentType)
        design = app.activeProduct

        # Get the root component of the active design.
        rootComp = design.rootComponent

        # Create a new sketch on the xy plane.
        sketch = rootComp.sketches.add(rootComp.xYConstructionPlane)

        # Create an object collection for the points.
        points = adsk.core.ObjectCollection.create()

        # Define the points the spline with fit through.
        points.add(adsk.core.Point3D.create(0, 0, 0))
        points.add(adsk.core.Point3D.create(5, 1, 0))
        points.add(adsk.core.Point3D.create(6, 4, 3))
        points.add(adsk.core.Point3D.create(7, 6, 6))
        points.add(adsk.core.Point3D.create(2, 3, 0))
        points.add(adsk.core.Point3D.create(0, 1, 0))

        for i in range(points.count-1):
            pt1 = points.item(i)
            pt2 = points.item(i+1)
            sketch.sketchCurves.sketchLines.addByTwoPoints(pt1, pt2)
        
    except:
        if ui:
            ui.messageBox('Failed:\n{}'.format(traceback.format_exc()))

Thanks,

Marshal

Re: Python script to create a chain of lines

ekinsb — Mon, 06 Nov 2017 17:36:59 GMT

The code that Marshal gave you is good and will work. However, the result may be slightly different than what you expect. It creates five completely independent lines. Their endpoints happen to be at the same coordinate but if you use the mouse to drag one of the end points you'll find that the lines are not connected. Here's a slight change to the above code so that existing sketch points are used to create the new lines.

        for i in range(points.count-1):
            if i == 0:
                pt1 = points.item(i)
            else:
                pt1 = lastLine.endSketchPoint

            pt2 = points.item(i+1)
            lastLine = sketch.sketchCurves.sketchLines.addByTwoPoints(pt1, pt2)

Re: Python script to create a chain of lines

JeromeBriot — Mon, 06 Nov 2017 21:23:25 GMT

Same code for a closed polygon:

    lines = sketch.sketchCurves.sketchLines

    pt1 = points.item(0)
    pt2 = points.item(1)
    firstLine = lines.addByTwoPoints(pt1, pt2)
    lastLine = firstLine

    for i in range(1,points.count-1):
        pt1 = lastLine.endSketchPoint
        pt2 = points.item(i+1)
        lastLine = lines.addByTwoPoints(pt1, pt2)

    pt1 = lastLine.endSketchPoint
    pt2 = firstLine.startSketchPoint
    lines.addByTwoPoints(pt1, pt2)

Re: Python script to create a chain of lines

Anonymous — Mon, 02 Mar 2020 02:28:08 GMT

Hi Brian,

this is cool...it works, but could you explain what's happening, I try to wrap my head around it but I'm having a hard time.

Let's say I was trying to make a sketch of a closed square. I wrote this:

points = adsk.core.ObjectCollection.create()

points.add(adsk.core.Point3D.create(0,0,0))

points.add(adsk.core.Point3D.create(0,2,0))

points.add(adsk.core.Point3D.create(2,2,0))

points.add(adsk.core.Point3D.create(2,0,0))

points.add(adsk.core.Point3D.create(0,0,0))

Then I added your lines and it works, I have a closed square in a sketch. But...how? So if I am not mistaken: adsk.core.ObjectCollection.create() creates an object called "points" that will include the points below. How does it put it in my sketch?

Also, can you break down your loop? I'm sorry if I'm asking too much or if I sound like a newb...I did coding in college 12 years ago and I'm trying to dig this back to the surface of my memory but it's hidden way deep in there

Thanks a lot, I appreciate it 🙂