Python Bounding Box Error

[isocam]

Can anybody help?

Can somebody try the following to see if it is the script fault or the fault of Fusion 360?

Please create a simple rectangle sketch 100mm x 50mm and extrude it by 10mm

Obviously, if you run the following script, you should get 100mm x 50mm x 10mm

Here is my script:

import traceback
import adsk.fusion
import adsk.core

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

comp: adsk.fusion.Component = des.activeComponent

bBox: adsk.core.BoundingBox3D = comp.boundingBox

maxPnt: adsk.core.Point3D = bBox.maxPoint

minPnt: adsk.core.Point3D = bBox.minPoint

length = abs(maxPnt.x - minPnt.x)

width = abs(maxPnt.y - minPnt.y)

height = abs(maxPnt.z - minPnt.z)

unitsMgr: adsk.core.UnitsManager = des.unitsManager

defLenUnit = unitsMgr.defaultLengthUnits

ratio = unitsMgr.convert(1, unitsMgr.internalUnits, defLenUnit)

msg = [
f'length : {length * ratio} {defLenUnit}',
f'width : {width * ratio} {defLenUnit}',
f'height : {height * ratio} {defLenUnit}',
]

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

I am getting a 0.02 increase on all dimensions.

Can I please ask if anybody else is getting the same error?

Many thanks in advance!

Darren

[kandennti · Accepted solution]

Hi @isocam .

The Bounding property is not very accurate.

https://forums.autodesk.com/t5/fusion-360-api-and-scripts/non-minimum-profile-boundingbox-is-it-a-bu... 

For more accurate results, it is better to use MeasureManager.getOrientedBoundingBox method.

https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-DE730595-9235-4DA1-8096-22A058921819 

I tried this method, but it is not supported for Component.
Therefore, I created a sample that processes all BRepBodies in a Component.

# Fusion360API Python script

import traceback
import adsk.fusion
import adsk.core

def run(context):
    ui = adsk.core.UserInterface.cast(None)
    try:
        app: adsk.fusion.Application = adsk.core.Application.get()
        ui = app.userInterface
        des: adsk.fusion.Design = app.activeProduct
        comp: adsk.fusion.Component = des.activeComponent

        # get OrientedBoundingBox
        measMgr: adsk.core.MeasureManager = app.measureManager
        OrientedBBoies = []
        for body in comp.bRepBodies:
            OrientedBBoies.append(
                measMgr.getOrientedBoundingBox(
                    body,
                    comp.yConstructionAxis.geometry.direction,
                    comp.xConstructionAxis.geometry.direction
                )
            )

        # get Temporary BRepBody
        tmpMgr: adsk.fusion.TemporaryBRepManager = adsk.fusion.TemporaryBRepManager.get()
        tmpBodies = []
        for bBox in OrientedBBoies:
            tmpBodies .append(
                tmpMgr.createBox(bBox)
            )

        # get UnionBody
        unionBody: adsk.fusion.BRepBody = tmpBodies[0]
        if len(tmpBodies) > 1:
            for body in tmpBodies[1:]:
                tmpMgr.booleanOperation(
                    unionBody,
                    body,
                    adsk.fusion.BooleanTypes.UnionBooleanType
                )

        # get UnionBody-OrientedBoundingBox
        OrientedBBox: adsk.core.OrientedBoundingBox3D = measMgr.getOrientedBoundingBox(
            unionBody,
            comp.yConstructionAxis.geometry.direction,
            comp.xConstructionAxis.geometry.direction
        )

        unitsMgr: adsk.core.UnitsManager = des.unitsManager
        defLenUnit = unitsMgr.defaultLengthUnits
        ratio = unitsMgr.convert(1, unitsMgr.internalUnits, defLenUnit)

        msg = [
            f'length : {OrientedBBox.length * ratio} {defLenUnit}',
            f'width : {OrientedBBox.width * ratio} {defLenUnit}',
            f'height : {OrientedBBox.height * ratio} {defLenUnit}',
        ]

        ui.messageBox('\n'.join(msg))

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

Also, the indentation of the code is maintained when this is used.