mesh.VertexColors.SetColors not working in Python script

Scripting
1 
The code below worked for jordy1989 to color a mesh:

 Dim colors As System.Drawing.Color() = New System.Drawing.Color(Mesh.Vertices.Count - 1) {}
            For i As Integer = 0 To Mesh.Vertices.Count - 1
                Dim z As Double = Mesh.Vertices(i).Z

                If z < 10 Then
                    colors(i) = Drawing.Color.Red
                Else
                    colors(i) = Drawing.Color.Green
                End If
            Next
            Mesh.VertexColors.SetColors(colors)

How do I write this in a Python script using Rhino common calls? I cannot figure how to replace the line:

Dim colors As System.Drawing.Color() = New System.Drawing.Color(Mesh.Vertices.Count - 1) {}

I tried:

	vcount = mesh.Vertices.Count
	colors = System.Drawing.Color[vcount]

but Python complains: Message: expected Array[Type], got int

I cannot use a list instead as the call to mesh.VertexColors.SetColors(colors) requires an array and not a simple Python list.

As a work around I am using:

for c in colors: mesh.VertexColors.Add(c)

but this is slow for my 20M face meshes. Please help!

Regards,
Terry.

2

Hi Terry,

I’m on my phone so this is without testing. But since you just posted it might help you enough to keep you moving.

Does this help:
http://www.ironpython.info/index.php?title=Typed_Arrays_in_IronPython

-Willem

1 Like
3

Willem,

Perfect help. From the documentation you pointed to I used:

from System import Array
colors = Array.CreateInstance(Color, num_colors)

Now the colors load 6X faster for a mesh with 2.2M vertices.

I am so happy!

Regards,
Terry.

2 Likes
4

Here’s an alternative way, to me it’s more comprehensible

from System.Drawing import Color
from System import Array

colors = Array[Color](colors_list)