FeaturePython shape, union sphere and cylinder

[fosselius]

I want to create a visual shape in a FeaturePython that consists of a union of a cylinder and a sphere, what is the best way to achieve this?
The shape is going to visualize a joints orientation and limits in my "RobotCreator" workbench.

Currently i only have a sphere that is implemented like this:

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def execute(self, fp):
	fp.Shape = Part.makeSphere(1)
	

In the FreeCAD python terminal i can run:

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App.ActiveDocument.addObject("Part::Sphere","Sphere")
App.ActiveDocument.addObject("Part::Cylinder","Cylinder")
FreeCAD.getDocument("Unnamed").getObject("Cylinder").Angle = 180.00
App.activeDocument().Fusion.Shapes = [App.activeDocument().Sphere,App.activeDocument().Cylinder,]
shapeThatIWant = FreeCAD.getDocument("Unnamed").getObject("Fusion").Shape
// remove sphere
// remove cylinder
// remove fusion

But it feels a bit silly to create and delete objects in the active document just to get the shape i need..

Screenshot from 2017-11-03 08-22-52.png (33.14 KiB) Viewed 645 times

[DeepSOIC]

Currently i only have a sphere that is implemented like this:

Code: Select all

def execute(self, fp):
	fp.Shape = Part.makeSphere(1)
	

Looks like you are on a right track.
fp.Shape = Part.makeSphere(1).fuse(Part.makeCylinder(...)) and so on

If the shape is the same all the time, it might be a good idea to load up a brep file instead of computing the shape every time.

Or you might want to create a visual-only shape for this purpose. Then you should use Coin (from pivy import coin), create stuff with it and add it to node of viewprovider of your feature. That is outside of my comfort zone, for sure. There is an example here: Scripted objects

[fosselius]

Now this was what i was after! Thank you!

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    fp.Shape = Part.makeSphere(1).fuse(Part.makeCylinder(2,0.2,App.Vector(0,0,-0.1),App.Vector(0,0,1),180))

Screenshot from 2017-11-03 13-56-51.png (22.81 KiB) Viewed 620 times

now its time for pose

Here is an example of the "joint" structure i try to visualize and will later generate from this "joint" object

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<joint name="Joint" type="revolute">
  <parent>Link1</parent>
  <child>Link2</child>
  <pose>0 0 0 0 0 0</pose> // derived from joint object
  <axis>
    <xyz>0 0 1</xyz> // orientation of disc
    <limit>
      <lower>-0.785398</lower> // visualized as pie/disc
      <upper>0.785398</upper> // visualized as pie/disc
    </limit>
  </axis>
 </joint>