Flow Object in Python

Scripting
1

Hi everyone,
I tried to translate this code:
Flow Object in VB
into Python. But all I get is the ‘namespace#’ error:
“attribute ‘FlowObject’ of ‘namespace#’ object is read-only”.
I am fairly new to Rhino scripting and I didn’t know where to look for the flowobject method in the Rhino script methods.
So now my question: How can I script a Flow Object command in python? How is the “local = Yes” boolean set in this command?
Thanks a lot! Cheers,
Benjamin

2

FlowObject is not in Python/rhinoscriptsyntax V5, and does not appear to have been implemented yet for V6 either…

Edit -

Following is an implementation in RhinoCommon that works in V5 or V6.
It is very simple with no error checking or curve end pick detection - flows from one curve to the other using their natural start points and stretch=yes.

import rhinoscriptsyntax as rs
import scriptcontext as sc
import Rhino

def TestFlowMorph():
    objID=rs.GetObject("Select object to flow")
    bcID=rs.GetObject("Pick base curve",4)
    tcID=rs.GetObject("Pick target curve",4)
    
    obj=sc.doc.Objects.Find(objID).Geometry
    bc=sc.doc.Objects.Find(bcID).Geometry
    tc=sc.doc.Objects.Find(tcID).Geometry
    
    flow=Rhino.Geometry.Morphs.FlowSpaceMorph(bc,tc,False)
    rc=flow.Morph(obj)
    if rc:
        sc.doc.Objects.AddBrep(obj)
        sc.doc.Views.Redraw()
TestFlowMorph()

–Mitch

3

Thanks Mitch!
I will implement your Solution tomorrow!
Cheers,
Benjamin

4

Hi @Helvetosaur,
I tried out your solution on a mesh… Of course your code expects a brep. Is there a posibility to flow with a mesh?

  • Edit

Found out how your code works with a mesh. I still need the Local=Yes option though. Is there a possible way to give this option to the function?

Cheers,
Benjamin

5

Yes, of course, you can just change the line

sc.doc.Objects.AddBrep(obj)

to

sc.doc.Objects.Add(obj)

and it should work for all geometry objects. That being said…

This morning I have been playing around with “encapsulating” the whole thing into a Python method that will work like the (vb) Rhinoscript. It’s more complicated than I thought, there are a lot of cases to consider - and what looks like a bug I’ve run across. I’ll post the result a little later once I have figured out what’s going on there.

–Mitch

6

OK, I think I’ve got it here… the little “bug” was a bit hard to track down. It’s amazing how much time you can end up spending on this.

The definition below should behave essentially like the Rhinoscript Rhino.FlowObject() method. Just copy/paste the whole first def part (up to return IDs) at the top of your script, then you can call it as a method like any other.

It has all the same arguments as Rhino.FlowObject(): the first three - the object(s) and two curves - are required, the others are optional (copy, etc.) and will revert to default values if you do not specify them. You can supply either a single object or list of objects to flow; it returns the same if successful. Should work with (any combination of) points, curves, surfaces, polysurfaces, extrusions, meshes.

If you find bugs (likely), let me know…

FlowObject.py (2.2 KB)

–Mitch

7

Hi @Helvetosaur,
I tested your script. I am still amazed. It works and gives similar results as the Flow command in Rhino directly. One Thing I need anyways: The Local=Yes is not available for this Flow command altough I need it. Is this option somewhere?
I worked my way around now with rs.Command(“Flow”) by selecting the Curves over ID’s. I will upload an example file tomorrow so you know what I am talking about.
Thank you so much!
Cheers,
Benjamin

8

Unfortunately not, this control does not appear to be exposed in the RhinoCommon SDK for the moment… So I guess your workaround scripting rs.Command("Flow) is about the only way if you need that.

–Mitch

9

Hey Guys,

i need to use the definition above but i’m getting the same error :Message: attribute ‘FlowSpaceMorph’ of ‘namespace#’ object is read-only

i’m new to Rhino scripting so i can’t understand what is wrong , any help?

10

Hi Mohamad,

It works here in the Beta version, could it be you are testing on V5?

-WIllem