Using Overloads with DecomposeAffine

Scripting
1

Hi-

I’m relatively new to using python in Rhino and am trying to understand the use of Overloads with Transform.DecomposeAffine. When enter the following:

block = rs.GetObject("",4096)
XForm = rs.BlockInstanceXform(block)
decompAff = Rhino.Geometry.Transform.DecomposeAffine.Overloads[Transform, Vector3d](XForm)
print decompAff

I get “Message: ‘method_descriptor’ object has no attribute ‘Overloads’” error. Is this the correct syntax? Or is there a step I’m missing?

Thanks,
David

2

Hi @David_Moreau,

some methods support Overloads and some do not. If you cannot get the Overloads in the python script editor after typing the method ending with a dot like this:

Rhino.Geometry.Transform.Decompose.

you can setup the variables the method is supposed to return as “out” before calling the method. Once the method is called it returns a single boolean value, if it is True, the out values have been changed.

And example with your code might look like this:

import Rhino
import scriptcontext
import rhinoscriptsyntax as rs
import clr

def DoSomething():

    block = rs.GetObject("Select block", rs.filter.instance, True, False)
    if not block: return
    
    block_xform = rs.BlockInstanceXform(block)
    
    outXform = clr.StrongBox[Rhino.Geometry.Transform]()
    outVector = clr.StrongBox[Rhino.Geometry.Vector3d]()
    
    rc = block_xform.DecomposeAffine(outXform, outVector)
    if not rc: return
    
    print outXform.Value
    print outVector.Value
    
DoSomething()

You might also take a look here for further info about python and Overloads:

_
c.

3

Thanks so much. This really helps. Points me in the right direction.