internal validation error when analysing interference multiple times in a script

[nnamfoh]

I'm experimenting with different uses of the interference calculation in Fusion 360.

One example I'm trying to create is generating the interference of an interfernce body. For example if you create a venn diagram with 3 triangulated circles you get an interior intersection of the 3 circles and 3 outer portions that are the intersection of only two models. I try to create this using this code (below) but I get a InternalValidationError. What is causing this error. I have similar issues in other scripts wheverer I try to calculate and interference multiple times.

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


        # Create a document.
        doc = app.documents.add(adsk.core.DocumentTypes.FusionDesignDocumentType)

        product = app.activeProduct
        design = adsk.fusion.Design.cast(product)
        design.designType = adsk.fusion.DesignTypes.DirectDesignType

        # Get the root component of the active design.
        rootComp = design.rootComponent
        features = rootComp.features

        # Create sketch circle on the xz plane.
        sketches = rootComp.sketches
        sketch = sketches.add(rootComp.xZConstructionPlane)
        sketchCircles = sketch.sketchCurves.sketchCircles
        centerPoint = adsk.core.Point3D.create(0, 0, 0)
        sketchCircles.addByCenterRadius(centerPoint, 10)

        # Create a collection of entities for extrude
        entities0 = adsk.core.ObjectCollection.create()
        entities0.add(sketch.profiles.item(0))

        # Create a cylinder with ExtrudeFeature using the profile above.
        extrudeFeats = features.extrudeFeatures
        extrudeFeatureInput = extrudeFeats.createInput(entities0, adsk.fusion.FeatureOperations.NewBodyFeatureOperation)
        extrudeFeatureInput.isSolid = True
        extrudeFeatureInput.setDistanceExtent(False, adsk.core.ValueInput.createByReal(2.5))
        extrudeFeature = extrudeFeats.add(extrudeFeatureInput)
        
        # Create second body to do interference
        sketch = sketches.add(rootComp.xZConstructionPlane)
        sketchCircles = sketch.sketchCurves.sketchCircles
        centerPoint = adsk.core.Point3D.create(5, 0, 0)
        sketchCircles.addByCenterRadius(centerPoint, 10)

        entities0.clear()
        entities0.add(sketch.profiles.item(0))

        # Create a cylinder with ExtrudeFeature using the profile above.
        extrudeFeatureInput = extrudeFeats.createInput(entities0, adsk.fusion.FeatureOperations.NewBodyFeatureOperation)
        extrudeFeatureInput.isSolid = True
        extrudeFeatureInput.setDistanceExtent(False, adsk.core.ValueInput.createByReal(2.5))
        extrudeFeature = extrudeFeats.add(extrudeFeatureInput)
        sketch = sketches.add(rootComp.xZConstructionPlane)
        sketchCircles = sketch.sketchCurves.sketchCircles
        centerPoint = adsk.core.Point3D.create(0, 5, 0)
        sketchCircles.addByCenterRadius(centerPoint, 10)

        entities0.clear()
        entities0.add(sketch.profiles.item(0))

        # Create a cylinder with ExtrudeFeature using the profile above.
        extrudeFeatureInput = extrudeFeats.createInput(entities0, adsk.fusion.FeatureOperations.NewBodyFeatureOperation)
        extrudeFeatureInput.isSolid = True
        extrudeFeatureInput.setDistanceExtent(False, adsk.core.ValueInput.createByReal(2.5))
        extrudeFeature = extrudeFeats.add(extrudeFeatureInput)
        

        # Create a collection of bodies
        bodies = adsk.core.ObjectCollection.create()
        for body in rootComp.bRepBodies:
            bodies.add(body)

        # Create InterferenceInput
        interferencInput = design.createInterferenceInput(bodies)

        # Analyze interference
        results = design.analyzeInterference(interferencInput)
        results.createBodies(True)
        
        intersection = rootComp.occurrences.item(0)
        newBodies = adsk.core.ObjectCollection.create()
        for body in intersection.component.bRepBodies:
            newBodies.add(body)
        #get next level of interference    
        interferenceInput0 = design.createInterferenceInput(newBodies)
        results1 = design.analyzeInterference(interferenceInput0)
        results.createBodies(True)

[frankzhang]

Hello, we are sorry you are having issues with this API, we have identified the problem and will provide a fix as soon as we can.

[nnamfoh]

In the mean time is there a work around that would could calculate the interference of these bodies?

[frankzhang · Accepted solution]

One workaround is to add two lines in your code as shown below in red:

# Analyze interference

results = design.analyzeInterference(interferencInput)

results.createBodies(True)

del interferencInput

del results

intersection = rootComp.occurrences.item(0)

newBodies = adsk.core.ObjectCollection.create()

for body in intersection.component.bRepBodies:

newBodies.add(body)

#get next level of interference

interferenceInput0 = design.createInterferenceInput(newBodies)

results1 = design.analyzeInterference(interferenceInput0)

results1.createBodies(True)

[nnamfoh]

Thank you that seems to work. Unfortunatly it does cost the data in results but I suppose I can save that to other data fields if  I need it.