How do I create a solid from ruled surfaces and faces?

[more11]

I have created ruled surfaces and faces in python. Now I want to create a solid from these.

First step was to create a shell, but that didn't work.

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shell = Part.makeShell(surfaces)
Part.show(shell)

This are the functions I use to populate surfaces:

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surface = Part.makeRuledSurface(wire, wire_1)
surfaces.append(surface)

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face = Part.Face(w)
surfaces.append(face)

[ulrich1a]

First step was to create a shell, but that didn't work.

It is difficult to say, what went wrong with the given information.
I would do: Part.show(surface) in the script or in the python console. And do the same with the other faces to. Typically you will see, what problem is there. It could be, that a face is not created due to problems in the underlaying geometry. It could be wrong orientation of wires, or different number of vertices in the wires or other problems.
You may have to further debug with Part.show(wire) and Part.show(wire_1)
If all faces do show up, try to make the shell with the gui commands.
I had cases, where it was possible to make the shell with the gui, but not with the script. I had to tune the script in this case.

Ulrich

[more11]

The problem seems to be the ruled surfaces. I cannot make shells from them in the Gui.



The cad file

[NormandC]

Your file has an insanely high number of faces to join. Maybe that's the problem?

Can't you extrapolate a BSpline curve rather than having so many little straight segments to create faces from?

[more11]

The problem is that the ruled suface is made from a Part.wire. The half circle Shape006 has few edges, and it cannot be added to a shell.

The Draft.BSpline is much better than both Draft.Dwire and Part.wire since the ruled surface is creted to the end. Making a ruled surface of a BSpline is much faster as well.

Thanks normandc!

[more11]

Now it looks like this with BSplines instead of dwires:



It is possible to create a shell in the gui, but not in code.

The drawing

I have created a small script which tries to create a shell from the objects in the file. I have also tried to reuse the code from the gui when creating the shell in the gui.

This is the script:

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import FreeCAD,Draft
import Part

surfaces = []
doc = FreeCAD.ActiveDocument
objs = doc.Objects
 
for obj in objs:
	surfaces.append(obj)
	a = obj.Name     # list the Name  of the object  (not modifiable)
	b = obj.Label      # list the Label of the object  (modifiable)
	try:
		c = obj.LabelText     # list the LabeText of the text (modifiable)
		print str(a) +" "+ str(b) +" "+ str(c)  # Displays the Name the Label and the text
	except:
		print str(a) +" "+ str(b)  # Displays the Name and the Label of the object

shell = Part.makeShell(surfaces)
Part.show(shell)
#shell = Part.Shell(surfaces)
#App.ActiveDocument.addObject('Part::Feature','Shell').Shape=shell.removeSplitter()
Gui.updateGui()

[shoogen]

Your shell is not closed. You need to add a top and a bottom face. You can create those faces by using something like

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topface=Part.Face(topwire)

[ulrich1a]

for obj in objs:
surfaces.append(obj)

The following code works for me:

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for obj in objs:
   for s_faces in obj.Shape.Faces:
      surfaces.append(s_faces)

Ulrich

[more11]

Thanks shoogen and Ulrich!

The only shape I still have problems with is ruled surface with bspline. I have made a script to make this:



Only the end faces are included in the shell.

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import math
import Draft
import Part
import FreeCAD

def frange(x, y, jump):
  while x < y:
    yield x
    x += jump

doc = FreeCAD.newDocument()
Gui.activeDocument().activeView().viewAxometric()
circle_1 = None
radius = 50
center = (0, 100.0, 0.0)
surfaces = []
for angle_i in frange(0.0, 95.0, 15.0):
	circle_points = []
	for circ_angle in frange(15.0, 360.0, 15.0):
		point = (center[0] + math.sin(math.radians(circ_angle)) * radius, center[1] + math.cos(math.radians(circ_angle)) * radius, center[2])
		circle_point = FreeCAD.Vector(point[0], point[1], point[2])
		circle_points.append(circle_point)
	circle = Draft.makeBSpline(circle_points, closed=True, face=False)
	if circle_1 != None:
		Draft.rotate(circle, angle_i, axis = FreeCAD.Vector(1.0, 0.0, 0.0))
		FreeCAD.ActiveDocument.addObject('Part::RuledSurface', 'Ruled Surface')
		circle_surface = FreeCAD.ActiveDocument.ActiveObject
		circle_surface.Curve1=(circle,[''])
		circle_surface.Curve2=(circle_1,[''])
		for f in circle_surface.Shape.Faces:
			surfaces.append(f) # not working
	if angle_i == 0.0 or angle_i == 90.0:
		end = Part.makeFilledFace([circle.Shape.Edge1])
		surfaces.append(end) # this works
	doc.recompute()
	Gui.SendMsgToActiveView("ViewFit")
	Gui.updateGui()
	circle_1 = circle
	
shell = Part.makeShell(surfaces)
Part.show(shell)

[ulrich1a]

This works for me:

Code: Select all

import math
import Draft
import Part
import FreeCAD

def frange(x, y, jump):
  while x < y:
    yield x
    x += jump

doc = FreeCAD.newDocument()
Gui.activeDocument().activeView().viewAxometric()
circle_1 = None
radius = 50
center = (0, 100.0, 0.0)
surfaces = []
for angle_i in frange(0.0, 95.0, 15.0):
   circle_points = []
   for circ_angle in frange(15.0, 360.0, 15.0):
      point = (center[0] + math.sin(math.radians(circ_angle)) * radius, center[1] + math.cos(math.radians(circ_angle)) * radius, center[2])
      circle_point = FreeCAD.Vector(point[0], point[1], point[2])
      circle_points.append(circle_point)
   circle = Draft.makeBSpline(circle_points, closed=True, face=False)
   if circle_1 != None:
      Draft.rotate(circle, angle_i, axis = FreeCAD.Vector(1.0, 0.0, 0.0))
      sector = Part.makeRuledSurface (circle.Shape, circle_1.Shape)
      for f in sector.Faces:
         surfaces.append(f) # now it works
   if angle_i == 0.0 or angle_i == 90.0:
      end = Part.makeFilledFace([circle.Shape.Edge1])
      surfaces.append(end) # this works
   doc.recompute()
   Gui.SendMsgToActiveView("ViewFit")
   Gui.updateGui()
   circle_1 = circle
   
shell = Part.makeShell(surfaces)
Part.show(shell)

Ulrich