Help me with Vertex Gradient in Python

Coding Python Support
1

Hello,
I’m trying to gradient a mesh with python script
I Found few scripts like this:

import bpy
from mathutils import Vector

flip = False
clearColors = True

obj = bpy.context.object
me = obj.data
#change this to change color, 0 = red, 1 = green, 2 = blue 
value = 0

bbox = [Vector(point) for point in obj.bound_box]
max_z = max(v.z for v in bbox)
min_z = min(v.z for v in bbox)
diff = max_z - min_z

mesh_loops = me.loops
color_loops = me.vertex_colors.active.data

if clearColors:
    for m_loop2, c_loop2 in zip(mesh_loops, color_loops):
        z = me.vertices[m_loop2.vertex.index].co.z

        c_loop2.color[0] = 0
        c_loop2.color[1] = 0
        c_loop2.color[2] = 0

for m_loop, c_loop in zip(mesh_loops, color_loops):
    z= me.vetrices[m_loop.vertex_index].co.z

    color = (z - min_z) / diff
    if flip:
       color = 1 - color

    c_loop.color[value] = color
    #c_loop.color[(value+1)%3] = color

The problem is I always get
“AttributeError: ‘NoneType’ object has no attribute ‘data’”
in “color_loops = me.vertex_colors.active.data”
It’s always me.vertex_colors.active.data

I don’t know what should I do.
Should I add something to the object for it to work?
I tried adding something to color_attributes or attributes but I don’t know what I should put there for the script to work…

Edit::
I added to Color Attributes: Attribute [Face corner->Byte Color]
And now the script goes
AttributeError: ‘MeshLoop’ object has no attribute ‘vertex’

;-;

2

That happens because there’s no vertex_colors layer, so vertex_colors.active is None.

Try this instead:

# [ some code ]

mesh_loops = me.loops
if not me.vertex_colors.active:
    me.vertex_colors.new(name = "Color")
color_loops = me.vertex_colors.active

# [ more code ]
3

Thanks for reply, I tried but now I’m getting

…line 23, in

TypeError: ‘MeshLoopColorLayer’ object is not iterable

Line 23 is

for m_loop2, c_loop2 in zip(mesh_loops, color_loops):
4

The MeshLoopColorLayer holds the vertex_loop list inside its data attribute…

you can use (you may need to correct other uses of this variable):

color_loops = me.vertex_colors.active.data

or in the zip:

for m_loop2, c_loop2 in zip(mesh_loops, color_loops.data):

A good way to find your way how the blender data is structured, is to open the Python Console, and check the objects and their attributes directly there. :wink:

5

When I’m adding .data back to

color_loops = me.vertex_colors.active

Everything goes back to

AttributeError: ‘MeshLoop’ object has no attribute ‘vertex’

Unfortunately I have zero knowledge about python… and it is probably first and last script I’ve gonna need from Python, so I would rather not spend year of my time to learn it for it :smile:

I saw the script working on 5:44

Also found few posts about gradient where similar scripts worked without problems.

Maybe my Blender is cursed or something…

6

In the code you posted, there are some errors… in your last AttributeError, you’re trying to access me.vertices[m_loop2.vertex.index].co.z but it really should be me.vertices[m_loop2.vertex_index].co.z.

I took all your code and fixed it, so this below should work now:

import bpy
from mathutils import Vector

flip = False
clearColors = True

obj = bpy.context.object
me = obj.data
#change this to change color, 0 = red, 1 = green, 2 = blue 
value = 0

bbox = [Vector(point) for point in obj.bound_box]
max_z = max(v.z for v in bbox)
min_z = min(v.z for v in bbox)
diff = max_z - min_z

mesh_loops = me.loops
if not me.vertex_colors.active:
    me.vertex_colors.new(name="Color")
color_loops = me.vertex_colors.active.data

if clearColors:
    for m_loop2, c_loop2 in zip(mesh_loops, color_loops):
        z = me.vertices[m_loop2.vertex_index].co.z

        c_loop2.color[0] = 0
        c_loop2.color[1] = 0
        c_loop2.color[2] = 0

for m_loop, c_loop in zip(mesh_loops, color_loops):
    z= me.vertices[m_loop.vertex_index].co.z

    color = (z - min_z) / diff
    if flip:
       color = 1 - color

    c_loop.color[value] = color
7

Thank you very much.
Sending a lot of love to you right now <3