Strange behavior on Occurrence.moveToComponent() with Occurrence.transform

[hajime2MRG3]

import adsk.core, adsk.fusion, adsk.cam, traceback

def run(context):
    ui = None
    try:
        app = adsk.core.Application.get()
        ui  = app.userInterface
        des = adsk.fusion.Design.cast(app.activeProduct)
        root_comp = des.rootComponent

        EYE = adsk.core.Matrix3D.create()
        o1 = root_comp.occurrences.addNewComponent(EYE)
        o2 = root_comp.occurrences.addNewComponent(EYE)
        o1_1 = o1.component.occurrences.addNewComponent(EYE)
        o1_2 = o1.component.occurrences.addNewComponent(EYE)

        ROT = adsk.core.Matrix3D.create()
        ROT.setToRotation(1., adsk.core.Vector3D.create(0, 0, 1), adsk.core.Point3D.create(0, 0, 0))

        o2_1 = o1_1.moveToComponent(o2)
        o2_1.transform = ROT
        print('Before:')
        print('o2_1.transform.asArray():')
        print(o2_1.transform.asArray())

        _ = o1_2.moveToComponent(o2)
        print('After:')
        print('o2_1.transform.asArray():')
        print(o2_1.transform.asArray())
    except:
        if ui:
            ui.messageBox('Failed:\n{}'.format(traceback.format_exc()))

The test code above results:

Before:
o2_1.transform.asArray():
(0.5403023058681398, -0.8414709848078965, 0.0, 0.0, 0.8414709848078965, 0.5403023058681398, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0)
After:
o2_1.transform.asArray():
(1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0)

Why does o1_2.moveToComponent(o2) affects on o2_1.transform?

[kandennti · Accepted solution]

Hi @hajime2MRG3 .

I used to have trouble getting the correct position.

Here's the cause.

In the case of Occurrence, the conversion will not complete. So, you need to determine the position.

・・・
        o2_1 = o1_1.moveToComponent(o2)
        o2_1.transform = ROT
        des.snapshots.add() # <-Here
        print('Before:')
        print('o2_1.transform.asArray():')
        print(o2_1.transform.asArray())
・・・

https://forums.autodesk.com/t5/fusion-360-api-and-scripts/transformation-on-occurrence-getting-reset... 

Also, I strongly recommend using the isPositionDependent property when invoking the command.

https://forums.autodesk.com/t5/fusion-360-api-and-scripts/quot-move-copy-quot-in-the-context-menu/m-... 

[hajime2MRG3]

Thank you kandennti,

I feel hard to distinguish which operation resets position. In GUI, a dialog pops up, but no warning or exception in scripts. Any good way to find unwanted resets?

[kandennti]

@hajime2MRG3 .

I don't have any better ideas.

It is very difficult to create an add-in that involves occurrence.

[hajime2MRG3]

Thank you again.