# Run this script to generate a UV map and Image with 1 pixel per face so each face has a single colour.

import bpy
import bmesh
import math

# Get selected/active object
obj = bpy.context.object
obj.update_from_editmode()
bpy.ops.object.mode_set(mode='EDIT')
bm = bmesh.from_edit_mesh(obj.data)

# Get count of faces
num_faces = len(bm.faces)

# Create UV map
obj.data.uv_textures.new("facepixels_"+str(num_faces))
uv_layer = bm.loops.layers.uv[0]
bm.faces.layers.tex.verify()

# Process each face and position each loop vertex around the centre point
faceidx = -1
for f in bm.faces:
    faceidx = faceidx + 1
    loopidx = -1
    numverts = len(f.loops)
    for l in f.loops:
        loopidx = loopidx + 1
        luv = l[uv_layer]
        luv.uv[0] = float(faceidx)
        luv.uv[1] = 0.5