Importing vertex color for bmesh

Coding Python Support
#1

Hello,
I am trying to update a script to bmesh for importing vertex color.
But all my attempts have failed.
Here is my code:


import bpy,mathutils
 
# 5 vertex with x,y,z coordinates
vertex = [1.0, 0.0, -1.0, -1.0, 0.0, -1.0, 1.0, 0.0, 1.0, -1.0, 0.0, 1.0, -1.0, 0.78, -1.8]
# 2 faces (aquad and a tri
faces = [1, 0, 2, 3, 4, 0, 1, 0]
# the vertex color (by vertex index)
polypaint = [(255, 3, 0), (10, 0, 255), (81, 255, 0), (77, 255, 0), (19, 253, 0)]
 
me = bpy.data.meshes.new('Mesh')
 
me.vertices.add(len(vertex)/3)
me.vertices.foreach_set("co", vertex)
 
me.tessfaces.add(len(faces)/4)
me.tessfaces.foreach_set("vertices_raw",faces)
 
vertexColor = me.vertex_colors.new()
 
me.update()
for poly in me.polygons:
    print("face ",poly.index)
    for loop_index in poly.loop_indices:
        loop = me.loops[loop_index]
        v = loop.vertex_index
        print("vertex ",v)
        color = polypaint[v]
        print("color ",color,"
")
        vertexColor.data[poly.index].color = mathutils.Color([color[0]/255,color[1]/255,color[2]/255])
 
 
# another method, same result:
# me.update(calc_tessface=True)
# for i in range(len(me.tessfaces)):
    # for j in range(len(me.tessfaces[i].vertices)):
        # color = polypaint[me.tessfaces[i].vertices[j]]
        # vertexColor.data[i].color = mathutils.Color([color[0]/255,color[1]/255,color[2]/255])
        # print(mathutils.Color([color[0]/255,color[1]/255,color[2]/255]))
        # print(vertexColor.data[i].color,"
")
ob = bpy.data.objects.new("obj", me)
bpy.context.scene.objects.link(ob)

Blender crash with this two methods…
What is the right way to create a new mesh with vertex painting?

#2

Well, you’re not alone. I’ve tried to update one of my script that paint vertexcolors, but it do not work with bmesh.
Perhaps something is broken, perhaps bmesh is not finished yet, i don’t know.
I’ve already posted some messages here about that.

good luck.

#3

Hello raphael,
the Blender script ‘vertexpaint_dirt.py’ can help us, it works fine with bmesh.

I think that maybe there is need to update something in the mesh…

#4

I have found the problem:
we need to add vertex_color after linking the mesh to an object:


import bpy,mathutils
print("
	------")
vertex = [1.0, 0.0, -1.0, -1.0, 0.0, -1.0, 1.0, 0.0, 1.0, -1.0, 0.0, 1.0, -1.0, 0.78, -1.8]
faces = [1, 0, 2, 3, 4, 0, 1, 0]
polypaint = [(255, 3, 0), (10, 0, 255), (81, 255, 0), (77, 255, 0), (19, 253, 0)]
#----
me = bpy.data.meshes.new('Mesh')
me.vertices.add(len(vertex)/3)
me.vertices.foreach_set("co", vertex)
me.tessfaces.add(len(faces)/4)
me.tessfaces.foreach_set("vertices_raw",faces)
me.update()
#----
ob = bpy.data.objects.new("obj", me)
bpy.context.scene.objects.link(ob)
# ----
vertexColor = me.vertex_colors.new()
i=0
for poly in me.polygons:
    print("face ",poly.index)
    for loop_index in poly.loop_indices:
        loop = me.loops[loop_index]
        v = loop.vertex_index
        print("vertex ",v)
        color = polypaint[v]
        print("color ",color,"
")
        vertexColor.data[i].color = mathutils.Color([color[0]/255,color[1]/255,color[2]/255])
        i+=1
#5

Hi,

Congratulation, and thanks a lot for this solution !