__author__ = 'thoth'

import bpy
import bmesh
from math import *
from mathutils import *

def set_uvs_for_face(bm, fi, uv_layer):
    face = bm.faces[fi]
    normal = face.normal
    dx=abs(normal[0])
    dy=abs(normal[1])
    dz=abs(normal[2])

    if (dz > dx):
        u = Vector([1,0,0])
        if (dz>dy):
            v = Vector([0,1,0])
        else:
            v = Vector([0,0,1])
    else:
        v = Vector([0,0,1])
        if dx>dy:
            u = Vector([0,1,0])
        else:
            u = Vector([1,0,0])
    for i in range(len(face.loops)):
        l = face.loops[i]
        l[uv_layer].uv = [ u.dot(l.vert.co),
                           v.dot(l.vert.co)]

def set_uvs(mesh, name=None):
    
    if name is None:
        if 0<len(mesh.uv_textures):
            uv = mesh.uv_textures[0]
        else:
            uv = mesh.uv_textures.new("cubic")
    else:
        uv = mesh.uv_textures.get(name)
        if uv is None:
            uv = mesh.uv_textures.new(name)
            
    bm = bmesh.new()
    bm.from_mesh(mesh)
    bm.faces.ensure_lookup_table()
    
    uv_layer = bm.loops.layers.uv[uv.name]
    
    for fi in range(len(bm.faces)):
        set_uvs_for_face(bm, fi, uv_layer)
    
    bm.to_mesh(mesh)

#
#
#

mode = bpy.context.mode
if 'OBJECT' != mode:
    bpy.ops.object.mode_set(mode='OBJECT')

obj = bpy.context.active_object
set_uvs(obj.data)

if 'OBJECT' != mode:
    bpy.ops.object.mode_set(mode = mode)

#