i tried to use bmesh to get the facenormals, but when tested it the value of all normals were null.

Code:

import bpy import bmesh ob = bpy.context.active_object me = ob.data bm = bmesh.new() bm.from_mesh(me) print('bmesh:', bm) for f in bm.faces:     print('face index:', f.index ,' and face normal:', f.normal)

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console output:
face index: 0 and face normal: <Vector (0.0000, 0.0000, 0.0000)>
face index: 1 and face normal: <Vector (0.0000, 0.0000, 0.0000)>
face index: 2 and face normal: <Vector (0.0000, 0.0000, 0.0000)>
face index: 3 and face normal: <Vector (0.0000, 0.0000, 0.0000)>
face index: 4 and face normal: <Vector (0.0000, 0.0000, 0.0000)>
face index: 5 and face normal: <Vector (0.0000, 0.0000, 0.0000)>

were did i went wrong or is it not finished yet?

dunno if this is intended this way, but if you call normal_update(), everything seems fine

Code:

import bpy import bmesh ob = bpy.context.active_object me = ob.data bm = bmesh.new() bm.from_mesh(me) bm.normal_update() print('bmesh:', bm) for f in bm.faces:     print('face index:', f.index ,' and face normal:', f.normal)

however, if i do
me.calc_normals()
all print() commands cause an error, which won't be shown in console oO
_________________
I'm sitting, waiting, wishing, building Blender in superstition...

im not a programmer and i really have some troubles with to anderstand the api. now i see the normal_update(). its very foggy from were im standing....

thanks a lot CoDEmanX.
it works
i did some more tryouts in selecting and mesh editing, well...
in the console window you can see whats going on.
theres a problem with the split() and the transform.
without bmesh: bpy.context.active_object.data.polygons this is possible.
i will search the api....

Code:

import bpy import bmesh def rotFaces(rotval, arrsel, bme):     for f in arrsel:         f.select = True     print('faces in array: ', arrsel)     for f in bme.faces:         print('Test selected index:', f.index, f.select) #    bpy.ops.object.mode_set(mode = 'EDIT', toggle = False) #    bpy.ops.mesh.split() #    bpy.ops.transform.rotate(value=(rotval), axis=(0,0,1)) #    bpy.ops.object.mode_set(mode = 'OBJECT', toggle = False)     for f in bme.faces:         f.select = False      ob = bpy.context.active_object me = ob.data bm = bmesh.new() bm.from_mesh(me) bm.normal_update() print('selected bmesh:', bm)    bpy.ops.object.mode_set(mode = 'EDIT', toggle = False) bpy.ops.mesh.select_all(action='DESELECT') bpy.context.scene.tool_settings.mesh_select_mode = (False, False, True) bpy.ops.object.mode_set(mode = 'OBJECT', toggle = False)     for f in bm.faces:     print('face index:', f.index ,' and face normal:', f.normal) xminus = [] yminus = [] yplus = [] for f in bm.faces:     if f.normal[0] < 0:         xminus.append(f) for f in bm.faces:     if f.normal[1] < 0:         yminus.append(f) for f in bm.faces:     if f.normal[1] > 0:         yplus.append(f)                         print('xminus: ', xminus) print('yminus: ', yminus) print('yplus: ', yplus) rotv = 3.141529 rotFaces(rotv, xminus, bm) bm.to_mesh(me) rotv = 3.141529/2 rotFaces(rotv, yminus, bm) bm.to_mesh(me) rotv = -3.141529/2 rotFaces(rotv, yplus, bm) bm.to_mesh(me)