Cone isExpanding

[rolandas_vegis]

How to find out whether a cone is expanding or not? Cone object doesn’t have that property and there doesn’t seem to be a way to calculate it from existing properties. Inventor Cone object has isExpanding property.

[marshaltu]

Hello,

There is no expanding property in geometry object "Cone". It would be good if you can explain a little bit about the workflow what you are going to do. We can probably find a workaround for you.

Thanks,

Marshal

[rolandas_vegis]

Was writing a method to calculate whether a cylinder is interior or exterior. How should I calculate it for cones without the is expanding property?

[marshaltu]

Hello,

I assume there is a context for cylinder or cone. Otherwise it seems that there is no way to calculate that. For the example the snapshot shows. There are two cone surfaces: interior and exterior. We can differentiate it by the normal on parameter point (0.5, 0.5). 

Thanks,

Marshal

import adsk.core, adsk.fusion, traceback

def run(context):
  ui = None
  try:
    app = adsk.core.Application.get()
    ui  = app.userInterface

    face = adsk.fusion.BRepFace.cast(ui.activeSelections.item(0).entity)
    res, normal = face.evaluator.getNormalAtParameter(adsk.core.Point2D.create(0.5, 0.5))

    ui.messageBox('Axis is {}, {}, {}'.format(normal.x, normal.y, normal.z))

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

[marshaltu]

I realized the previous solution would not work if there is only one cone surface. The following codes just show how to judge if cone is interior or exterior by the angle between the normal and axis of cone surface. If it is larger than 90 degree, the cone is interior. Otherwise it is exterior.

Thanks,

Marshal

import adsk.core, adsk.fusion, traceback
import math

def run(context):
  ui = None
  try:
    app = adsk.core.Application.get()
    ui  = app.userInterface

    face = adsk.fusion.BRepFace.cast(ui.activeSelections.item(0).entity)
    cone = adsk.core.Cone.cast(face.geometry)
    res, normal = face.evaluator.getNormalAtParameter(adsk.core.Point2D.create(0.5, 0.5))
    angle = normal.angleTo(cone.axis) * 180.0 / math.pi

    ui.messageBox('Axis is {}'.format(angle))

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

[VismantasKizelis]

Hello

It happens that cone axis returned by API does not always match the cone direction. I got a model of two cones pointing differend directions, but API returns Vector3D(0, 0, -1) for both of them. So one cone has angle between axis and normal >90 and other cone has angle <90 degrees, but both are exterior cones.

[marshaltu]

Hello,

It would be good if you share a copy of the design to me. I can take a look then.

Thanks,

Marshal

[VismantasKizelis]

Sure. Here is the link to the cones model.

[marshaltu · Accepted solution]

Hello,

I changed the codes a little bit. It should work well for your case now. Please give a try.

Thanks,

Marshal

import adsk.core, adsk.fusion, traceback
import math

def run(context):
  ui = None
  try:
    app = adsk.core.Application.get()
    ui  = app.userInterface

    face = adsk.fusion.BRepFace.cast(ui.activeSelections.item(0).entity)
    cone = adsk.core.Cone.cast(face.geometry)
    origin = cone.origin
    
    res, normal = face.evaluator.getNormalAtParameter(adsk.core.Point2D.create(0.5, 0.5))  
    res2, point = face.evaluator.getPointAtParameter(adsk.core.Point2D.create(0.5, 0.5))
    axis = adsk.core.Vector3D.create(point.x - origin.x, point.y - origin.y, point.z - origin.z)
    angle = normal.angleTo(axis) * 180.0 / math.pi

    ui.messageBox('Angle is {}'.format(angle))

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