topic Re: Splining through sketch points in Fusion API and Scripts Forum

Splining through sketch points

alongman1 — Fri, 07 Jan 2022 17:32:25 GMT

Hi,

I have posted previously about a problem within the same project. I am trying to capture an extruded volume of the same shape as a derived body, offset by a small distance. I have sliced the body in 2 directions and intersected these sketches. These intersections are for splines, to guide the lofts to generate the larger body. The problem is the numbering of the splines seems to be slightly random - the first 10 intersections seem to be numbered sensibly (ABABAB) from the nose and the tail, but something switches towards the middle and the sequence doesn't match up. I therefore get odd spline shapes, instead of the smooth rails I need between profiles. I have attached an image below. If anyone has any ideas on how to get the numbering of the splines to conform to some basic system, or how to figure out how to get the correct points in the splines that would be great. I have added the spline code below.

Note, I don't think the x and y constraints on which points get added to which spline are doing anything, as I believe this is the same result as a basic script adding odd and even points to different splines.

import adsk.core, adsk.fusion, adsk.cam, traceback

import math

def run(context):

ui = None

try:

app = adsk.core.Application.get()

ui = app.userInterface

product = app.activeProduct

design = adsk.fusion.Design.cast(product)

#get root component in active design

rootComp = design.rootComponent

#get construction planes

planes = rootComp.constructionPlanes

#create construction plane intput

#get sketches

sketches = rootComp.sketches

NumPrevSketches = 0

carHeight = 84.5

xySlices = 20

xzSlices = 75

Zmin = -24.5

#ignoring the bottom few sketches that arent curved

z0sketchNum = NumPrevSketches + xzSlices + math.floor((carHeight - Zmin)/xySlices)

sketchCount = sketches.count

splineSketches = sketchCount - z0sketchNum

for i in range(sketchCount😞

if i > z0sketchNum:

splinePoints1 = adsk.core.ObjectCollection.create()

splinePoints2 = adsk.core.ObjectCollection.create()

zSketch = sketches[i]

sketchPoints = zSketch.sketchPoints

numSketchPoints = sketchPoints.count

splinePoints1.add(sketchPoints[0])

for q in range(1, numSketchPoints😞

pnt0 = sketchPoints[q-1]

pnt1 = sketchPoints[q]

pos0 = adsk.fusion.SketchPoint.cast(pnt0)

pos1 = adsk.fusion.SketchPoint.cast(pnt1)

posArray0 = pos0.geometry.asArray()

posArray1 = pos1.geometry.asArray()

xVal0 = posArray0[0]

xVal1 = posArray1[0]

yVal0 = posArray0[1]

yVal1 = posArray1[1]

xDifPrev = xVal1 - xVal0

yDifPrev = yVal1 - yVal0

if yDifPrev >1 and xDifPrev < 14 :

splinePoints1.add(sketchPoints[q])

else:

splinePoints2.add(sketchPoints[q])

spline1 = zSketch.sketchCurves.sketchFittedSplines.add(splinePoints1)

spline2 = zSketch.sketchCurves.sketchFittedSplines.add(splinePoints2)

except:

if ui:

ui.messageBox('Failed:\n{}'.format(traceback.format_exc()))

Thanks in advance,

Andrew

Re: Splining through sketch points

alongman1 — Tue, 11 Jan 2022 09:57:40 GMT

*The numbering of intersection points [seems random], not splines.

Re: Splining through sketch points

kandennti — Thu, 13 Jan 2022 09:32:37 GMT

Hi @alongman1 .

I'd like to try it, but I didn't know what it meant.

Can you provide an f3d file for me to try?

Re: Splining through sketch points

alongman1 — Sat, 29 Jan 2022 20:01:01 GMT

@kandennti the f3z file is too large, how can I share it properly?

Re: Splining through sketch points

kandennti — Sun, 30 Jan 2022 14:00:29 GMT

Hi @alongman1 .

It does not have to be production data.
Do you have any simple data that can reproduce the same condition?

Re: Splining through sketch points

JeromeBriot — Sun, 30 Jan 2022 16:09:18 GMT

@alongman1 a écrit :

@kandennti the f3z file is too large, how can I share it properly?

Hello,

You can share a public link: How to share a Fusion 360 design

Splining through sketch points

MichaelT_123 — Mon, 31 Jan 2022 06:50:05 GMT

Hi AlongMan,

If the 'offset distance' is small in comparison with the object size, it is much simpler to find out the area of the surface you want to 'thicken' and multiply it by offset value.

For the single body, perhaps F360 UI and calculator would do the task

Regards

MichaelT

Re: Splining through sketch points

alongman1 — Mon, 31 Jan 2022 18:41:41 GMT

The public link is here: https://a360.co/3rdav72. Thank you @JeromeBriot.

@MichaelT_123 I am trying to automate the project entirely, so looking to avoid resorting to the UI, although I know the task can be completed relatively easily in the UI.