Part.Wire misses some Edges

[bernd]

I would like to make ONE Wire out of ALL Edges from the Screen and file attached. For some reason some Edges are missing (pink in the second screen is the wire). What I did:

Code: Select all

Part.show(Part.Wire(App.ActiveDocument.Compound.Shape.Edges))

Does someone has an idea how to make an wire out of the edges with OCCT >= 6.9 or how to trackle down the problem of the missing Edges.

BTW: Is it called non-manifold wire or is this term only used on faces and shells?

nonmanifold_wire.fcstd

(46.99 KiB) Downloaded 33 times

screen.jpg (70.27 KiB) Viewed 1903 times

screen1.jpg (97.18 KiB) Viewed 1903 times

[microelly2]

What happens when you first order the edges so that consecutive ones have common endpoints?
It will happen that you need to add some edges more than once because your figures is not a euler graph.

[chrisb]

Which FreeCAD version do you use?

[chrisb]

(Seems to independent from the current FreeCAD versions.)
microcelly2 is right: If you select arbitrary paths through your network without having more than 2 lines at one vertex, the upgrade tool creates a path wire. If I connect several of these wires I get a block.

Edit in blue

[tanderson69]

I would like to make ONE Wire out of ALL Edges from the Screen and file attached.

What are your plans for this wire?

I can't speak for freecads python api, but you won't find much algorithmic support in occt for such a wire.

[DeepSOIC]

nonmanifold_wire_DeepSOIC.fcstd

(49.17 KiB) Downloaded 33 times

How to:
1. BooleanFragments
2. w = Part.Wire(booleanfragments.Shape.Edges)
3. for e in booleanfragments.Shape.Edges: w.add(e)

After step 2, I got a wire with some edges missing. Re-adding them to the wire seems to have worked.

[bernd]

I would like to make ONE Wire out of ALL Edges from the Screen and file attached.

What are your plans for this wire?

If all Edges are connecte a Edgemesh generated with GMSH has connected Edges and is appropriate for an FEM calculation. It is like the CompSolids but just not in 3D (Solids vs CompSolids) but 1D instead (Edges vs. Wire). Same with Face and Shell you may remember we had a looooong discussion about the Shell some time ago before the BooleanFragments where available in FreeCAD.

@DeepSonic works great here too!

BTW: with OCCT < 6.9 this could be made with a Fusion, good too know with OCCT >= 6.9 it could be made with the BooleanFragments

nonmanifold_wire_DeepSOIC_FEM.fcstd

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screen.jpg (181 KiB) Viewed 1838 times

[tanderson69]

Curious, what does gmsh do with a compound of 'connected' edges?

[bernd]

Curious, what does gmsh do with a compound of 'connected' edges?

Same what GMSH meshes if you pass a Compound of "connected" Solids instead of one CompSolid or if you pass a Compound of "connected" Faces instead of one Shell or a Compound of "connected" Edges instead of one Wire. GMSH will mesh them in one big mesh but will not connect them means for the connected Edges in the mesh there will be at a vertex where 3 Edges meat there will be three nodes. Each Edge will have his own node, thus the Edges are not connected. If you pass one wire GMSH will make one Vertex at the point where the three edges are connected. GMSH just meshes what it gets. Means you need to pass the wire as brep.

bernd

[bernd]

How to:
1. BooleanFragments
2. w = Part.Wire(booleanfragments.Shape.Edges)
3. for e in booleanfragments.Shape.Edges: w.add(e)
.

All in Python. Load nonmanifold_wire.fcstd from first topic post

Code: Select all

import BOPTools.SplitFeatures
import Part
j = BOPTools.SplitFeatures.makeBooleanFragments(name='BooleanFragments')
j.Objects = App.ActiveDocument.Compound
j.Proxy.execute(j)
j.purgeTouched()
for obj in j.ViewObject.Proxy.claimChildren():
    obj.ViewObject.hide()

w = Part.Wire(j.Shape.Edges)
for e in j.Shape.Edges:
    w.add(e)

j.ViewObject.hide()
Part.show(w)