topic Re: Python: Using Scale Features at originConstructionPoint moves bodies. in Fusion API and Scripts Forum

Python: Using Scale Features at originConstructionPoint moves bodies.

Mehrab.Nasrabadi — Tue, 07 Mar 2023 00:46:53 GMT

Hello everyone,

I have a small problem when using the ScaleFeature. I want to iterate through all the bodies and then scale them non-uniformly. The point from which I want to scale should always be the origin of the component of the body. However, I have the problem that the bodies are scaled as I want but as soon as the ScaleFeature is executed the bodies move. I think it is either because of my declaration of the origin or because the scaleFeuture.add(...) does more than it should.🤔 But unfortunately, I'm not getting any smarter from this.

I am very grateful for any help and advice!

I have attached the culprit, maybe someone has the time and inclination to look over it!

Kind regards from Leipzig, Germany😊

import adsk.core import adsk.fusion import traceback def run(context): ui = None try: app: adsk.core.Application = adsk.core.Application.get() ui = app.userInterface design: adsk.fusion.Design = app.activeProduct design.designType = adsk.fusion.DesignTypes.ParametricDesignType rootComp: adsk.fusion.Component = design.rootComponent for i in range(0, rootComp.allOccurrences.count): occ = rootComp.allOccurrences.item(i) # Get the associated component. comp = occ.component # iterate over bodies for j in range(0, comp.bRepBodies.count): bodies: adsk.core.ObjectCollection = adsk.core.ObjectCollection.create() bodies.clear() body = comp.bRepBodies.item(j) body = body.createForAssemblyContext(occ) bodies.add(body) scalePoint = comp.originConstructionPoint.createForAssemblyContext(occ) ui.messageBox(str(scalePoint.geometry.asArray())) scaleFactor = adsk.core.ValueInput.createByReal(0.5) scaleFeatures = rootComp.features.scaleFeatures xScale = adsk.core.ValueInput.createByReal(float(1.55)) yScale = adsk.core.ValueInput.createByReal(float(1.45)) zScale = adsk.core.ValueInput.createByReal(float(1.35)) input = scaleFeatures.createInput(bodies, scalePoint, scaleFactor) input.setToNonUniform(xScale, yScale, zScale) scaleFeature = scaleFeatures.add(input) ui.messageBox(str(scalePoint.geometry.asArray()))

Re: Python: Using Scale Features at originConstructionPoint moves bodies.

kandennti — Tue, 07 Mar 2023 04:34:56 GMT

Hi @Mehrab.Nasrabadi .

You may not have finalized the position of the component after it has been moved.

https://forums.autodesk.com/t5/fusion-360-api-and-scripts/transformation-on-occurrence-getting-reset/m-p/8402626#M6887

https://forums.autodesk.com/t5/fusion-360-api-and-scripts/quot-move-copy-quot-in-the-context-menu/m-p/9443651#M9824

How about modifying it like this?

・・・ design: adsk.fusion.Design = app.activeProduct design.designType = adsk.fusion.DesignTypes.ParametricDesignType rootComp: adsk.fusion.Component = design.rootComponent design.snapshots.add() for i in range(0, rootComp.allOccurrences.count): ・・・

Re: Python: Using Scale Features at originConstructionPoint moves bodies.

Mehrab.Nasrabadi — Tue, 07 Mar 2023 17:07:59 GMT

at first this wasn't a solution for me because i also move the bodies in my script and that doesn't work with the line. but then i just changed my script a bit so that i first move and then scale. and that worked perfectly!

Thank you for your great help and your commitment to the community!

I have another small question, for which it's probably not really worth creating a new post.
It's about the creation of matrices, the setting of their rotation and translation is documented here : https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-GUID-b831d9f4-c231-4b9f-9b4d-658614ecdc79. But why is there no scaling? I mean I could get the individual positions from the transformation matrix and then multiply them by a scaling factor and then set them back to their position in the matrix (which unfortunately didn't work :D). But in my opinion, the methods of a transformation matrix also include scaling. It feels particularly problematic because fusion or many or possibly all CAD programs make a minimal error in the calculation or creation of transformation matrices and as soon as there is a small error in the input, this information is not accepted and the transformation matrix does not work.
But it is not that important because i have now my way to solve that problem!

Thank you and much love for you ❤️