Hi!
I’m using vertex colors to control texture splatting on a mesh. To speed up my shader, I simply scale the different splat textures by the colors channels, thus, vertex colors need to be normalized (for any vertex color, r + g + b == 1.0).
I posted about this on Blender Stack Exchange (Can Vertex Paint Normalize Color Channels?) and I managed to put together a small Add-On that adds a vertex color normalization option to meshes:
import bpy
import random
import math
from mathutils import Color, Vector
bl_info = {
"name": "Vertex Color Normalizer",
"description": "Allows the vertex colors of a mesh to be normalized (useful if colors control texture splatting).",
"author": "Markus Ewald",
"version": (1, 0),
"blender": (2, 65, 0),
"location": "View3D > Add > Mesh",
"warning": "", # used for warning icon and text in addons panel
"wiki_url": "http://wiki.blender.org/index.php/Extensions:2.5/Py/"
"Scripts/VertexColorNormalizer",
"category": "Paint"
}
class VertexColorNormalizer(bpy.types.Operator):
bl_idname = "object.normalize_vertex_colors"
bl_label = "Normalize Vertex Colors"
bl_description = "Normalize vertex colors to enable additive texture splatting"
def execute(self, context):
# What I want to do:
# - Iterate over the colors of all the vertices in active mesh
# - Normalize each color (divide by sqrt(r *r + g * g + b * b))
# - Assign it back to the vertex
for i in context.active_object.data.vertex_colors[0].data:
r = i.color[0]
g = i.color[1]
b = i.color[2]
magnitude = math.sqrt(r * r + g * g + b * b)
if magnitude > 1:
normalized_color = (r / magnitude, g / magnitude, c / magnitude)
i.color = Color((normalized_color))
return {'FINISHED'}
def register():
bpy.utils.register_class(VertexColorNormalizer)
if __name__ == "__main__":
register()
Is it possible to automatically do this as any vertices are modified by Blender (basically some kind of callback or hook function that I can toggle on and off for Blender’s vertex color paint mode)?
