[Solved] Is there a simple way to get all Vertex coords from a sketch?

[freedman]

Thank you Chris_G, that works!
I don't understand the code as yet but a quick test confirms this working. And Yes! We are in Sketch edit mode.

Hopefully this will clear a path for what seemed to be a very complicated issue.

Trying to describe what goes on here, I'm not that good in Python:

Code: Select all

for so in sel:
    for sub in so.SubElementNames:
        if "Vertex" in sub:
            n = eval(sub.lstrip('Vertex'))
            geo, pos = so.Object.getGeoVertexIndex(n-1)
            p = so.Object.getPoint(geo, pos)

It looks like we search the object for Sub element names looking for vertex, then store the vertex without attribute, I'm lost after that............
I got this from a search:

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…returns tuple (geoId, posId) of vertex at that index in the sketch. usage example: (geoId, posId) = App.ActiveDocument.Sketch.getGeoVertexIndex(int(Gui.Selection.getSelectionEx()[0].SubElementNames[0][6:])-1)

OK! I can see the path for this, I don't understand some of that but I do see the path.

I will reference this in the other posts on this topic.
This is good stuff!

[edwilliams16]

To get the local coordinates of a vertex, you apply the inverse of the global placement to the global position. You asked for this earlier.

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sel = Gui.Selection.getSelectionEx()[0]
vertexName = sel.SubElementNames[0]
if vertexName[0:6] == 'Vertex':
    vIndex = int(vertexName[6:])-1
    sk = App.ActiveDocument.getObject(sel.ObjectName)
    vGlobal = sk.Shape.Vertexes[vIndex].Point
    gpl = sk.getGlobalPlacement()
    vLocal = gpl.inverse().multVec(vGlobal)
    print(f'{sel.ObjectName} {vertexName} \nGlobal: {vGlobal} \nLocal: {vLocal}')
else:
    print('Select one vertex')
    

Select a vertex and run the macro.

[freedman]

edwilliams16, I did ask for that but I didn't like the solution , what you show is all calculated and will have rounding errors. I had an idea the raw data was in the object somewhere and that's what I get from what Chris_G did.

Paullee, change axis or go off axis and the data has calculated errors.

I'm still testing so I could be wrong.

Thanks all

[edwilliams16]

I may be making some brain-dead error, but @chrisb's method doesn't work consistently for me. If I select Vertex3 ofSketch, whose global coordinates are (10, -10, 5) and local coordinates (10, -10, 0) with the following Macro:

Code: Select all

sel = Gui.Selection.getSelectionEx()[0]
vertexName = sel.SubElementNames[0]
if vertexName[0:6] == 'Vertex':
    vIndex = int(vertexName[6:])-1
    sk = App.ActiveDocument.getObject(sel.ObjectName)
    vGlobal = sk.Shape.Vertexes[vIndex].Point
    gpl = sk.getGlobalPlacement()
    vLocal = gpl.inverse().multVec(vGlobal)
    print(f'{sel.ObjectName} {vertexName} \nGlobal: {vGlobal} \nLocal (calculated): {vLocal}')
    p = sel.Object.getPoint(*sel.Object.getGeoVertexIndex(vIndex))
    print(f'Local (from object) {p}')
    print (f'Equal? {p.isEqual(vLocal, 1E-7)}')
    for i in range(4):
        geo, pos = sel.Object.getGeoVertexIndex(i)
        print(f'geo {geo} pos {pos}')
        print(f' Vertex{i+1} {sel.Object.getPoint(geo, pos)}')
else:
    print('Select one vertex')

I get the correct coordinates, chrisb's method does not. OTOH, Vertex1 and Vertex2 are correct. Vertex4 is also incorrect

Here's the result, picking Vertex3 of Sketch

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12:24:26  Sketch Vertex3 
Global: Vector (10.0, -10.0, 5.0) 
Local (calculated from gpl): Vector (10.0, -10.0, 0.0)
12:24:26  Local (from object) Vector (10.0, 10.0, 0.0)
12:24:26  Equal? False
12:24:26  geo 0 pos 1
12:24:26   Vertex1 Vector (-10.0, 10.0, 0.0)
12:24:26  geo 0 pos 2
12:24:26   Vertex2 Vector (10.0, 10.0, 0.0)
12:24:26  geo 1 pos 1
12:24:26   Vertex3 Vector (10.0, 10.0, 0.0)
12:24:26  geo 1 pos 2
12:24:26   Vertex4 Vector (10.0, -10.0, 0.0)

[paullee]

Note :

The Edge or Vertex 'index' returned when Sketch is in Edit or Not will be different.

In Edit mode, the index return is exactly what you see in the edit panel ('basic Part Geometry').

Outside Edit mode, it refer to the Wires created (Part Topology)

See https://wiki.freecadweb.org/Topological_data_scripting

[paullee]

Paullee, change axis or go off axis and the data has calculated errors.

Not sure I get your meaning

May approach is similar to @Chris_G's, just my approach use Selection Observer.

So, the coordinate return is 'local'.

[edwilliams16]

Note :

The Edge or Vertex 'index' returned when Sketch is in Edit or Not will be different.

If I run my macro, I get identical results in or out of edit mode.

[paullee]

Probably we are talking about different things See below 2 screencaptures-


1. In Edit Mode, the highlighted Vertex is 8
- It is about the Part Geometry
- Every straight has 2 vertexes
- It is the End Vertex of the 4th Edges, so 8

2. Outside Edit Mode, the highlighted Vertex is 5
- It is the Wire (topological shape)
- It is the last Vertex of the Wire with 4 Edges, so 5

Test_ Observer_ 2.FCStd

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Screenshot from 2021-09-12 11-31-07.png (254.66 KiB) Viewed 1886 times

Screenshot from 2021-09-12 11-31-24.png (258.14 KiB) Viewed 1886 times

[freedman]

To test this there are two variables. 1) We need to be in sketch edit mode and 2) We need to attach the sketch to an off axis face.

Paullee, whenever I see the Z coord (see pic) as anything but 0.00 then I presume it's not local geometry of Sketcher X,Y,Z. When I see Z coords that are close to zero but not zero then I feel the results are global, they just appear as local because the sketch was created on the XY plane. If the sketch was created off axis then Z will be big time non-zero.

[paullee]

Copied the original sketch, translated and rotated it.

Now below steps:-

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# Select 'original' sketch
>>> s=Gui.Selection.getSelection()[0]

# Select the translated and rotated sketch
>>> ss=Gui.Selection.getSelection()[0]

# Print the (random) 3rd Geometry, 1st Vertex (StartPoint) coordinate ('local')
>>> s.Geometry[3].StartPoint
Vector (-35.999249, 36.64522212474619, 0.0)

# This is for the translated and rotated sketch
# Print the 3rd Geometry, 1st Vertex (StartPoint) coordinate ('local')
>>> ss.Geometry[3].StartPoint
Vector (-35.999249, 36.64522212474619, 0.0)
>>> 

Both return identical 'local coordinates'. May try attachment.

Test_ Observer_ 3.FCStd

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Screenshot from 2021-09-12 13-00-17.png (264.22 KiB) Viewed 1837 times