[Bf-python] How to copy MVerts?

[Ken Hughes]

Tron Thomas wrote:
> I am working with export geometry from Blender.  Currently when an 
> object like a cube is created, Blender only provide 8 vertices for that 
> cube.  This means that there are only 8 normal vectors.  However each 
> vertex of a cube is shared between 3 different face and therefore 24 
> normal vectors are needed to define all the faces for the cube.  I am 
> interested in copying each vertex so that there will be 24 vertices with 
> 24 normals vectors when defining the cube geometry.
> 
> By default Python creates additional references to objects rather than 
> copies.  Attempts to use copy.copy and copy.deepcopy on MVerts causes 
> run time errors.
> 
> How can I make copies of the cube vertices using the Python scripting 
> API's?

Try something like this:

#----------------
import Blender

me = Blender.Mesh.Get('Mesh')
verts = [v.co for v in me.verts]
verts += verts
me.verts.extend(v)

#----------------

me.vert.extend should accept a list of MVerts or PVerts also, but 
doesn't right now (and I discovered it also doesn't throw an exception 
if you do pass it these).

Ken