Vertex Color Map

setting vertex colors

first, run this code only on primitive objects until you understand what it does. this is for setting vertex colors of a vertex color map

	import bpy
	import random
	# start in object mode
	my_object = bpy.data.objects['Cube'].data
	color_map_collection = my_object.vertex_colors
	if len(color_map_collection) == 0:
	color_map_collection.new()
	"""
	let us assume for sake of brevity that there is now
	a vertex color map called 'Col'
	"""
	color_map = color_map_collection['Col']
	# or you could avoid using the vertex color map name
	# color_map = color_map_collection.active
	i = 0
	for poly in my_object.polygons:
	for idx in poly.loop_indices:
	rgb = [random.random() for i in range(3)]
	color_map.data[i].color = rgb
	i += 1
	# set to vertex paint mode to see the result
	bpy.ops.object.mode_set(mode='VERTEX_PAINT')

view raw vertex_colors.py hosted with ❤ by GitHub

getting vertex colors

getting vertex colors is similar but in reverse, remember that 1 vertex can be shared by several polygons and each polygon can set a different color for that vertex/index. Notice how the plane divided into 4 below has one central vertex which is shared by 4 surrounding polygons, each polygon has a different color for that vertex.

Material from vertex color map

this requires setting viewport shading from solid to texture.

	import bpy
	import random
	# start in object mode
	my_object = bpy.data.objects['Cube'].data
	color_map_collection = my_object.vertex_colors
	if len(color_map_collection) == 0:
	color_map_collection.new()
	"""
	let us assume for sake of brevity that there is now
	a vertex color map called 'Col'
	"""
	color_map = color_map_collection['Col']
	# or you could avoid using the vertex color map name
	# color_map = color_map_collection.active
	i = 0
	for poly in my_object.polygons:
	for idx in poly.loop_indices:
	rgb = [random.random() for i in range(3)]
	color_map.data[i].color = rgb
	i += 1
	mat = bpy.data.materials.new('vertex_material')
	mat.use_vertex_color_paint = True
	mat.use_vertex_color_light = True # material affected by lights
	my_object.materials.append(mat)
	# set viewport shading to texture to view this.

view raw material_from_vertex_color_map.py hosted with ❤ by GitHub