How do I Split a Mesh by UV Elements?

Using the Unwrap_UVW modifier's Flatten option, you can split the UV Coordinates into elements based on a threshold angle for easier texturing. The following scripted function allows you to detach the mesh faces based on the corresponding Map faces. (Remember, there is a one-to-one correspondence between their indices, so the task is relatively trivial - see Understanding Texture Coordinates).

SCRIPT

   fn splitMeshByUVElements mesh channel =
   (
       with undo off
       (
           local obj = copy mesh--copy the original object
           convertToMesh obj--convert to editable mesh
           while obj.numfaces > 0 do--repeat until all elements have been detached
           (
                 face_array = #(1)--init. an array including only face 1
                 cnt = 0--init. a counter  --repeat until the counter is higher than the faces stored in the array
                 while cnt < face_array.count do
                 (
                       cnt += 1 --increase the counter --get all map vertices used by the current map face in the collection array:
                       theVerts = meshop.getMapVertsUsingMapFace obj channel #(face_array[cnt])
                       --get all map faces used by these map vertices - --this gives us all neighbours of the current map face
                       theFaces = meshop.getMapFacesUsingMapVert obj channel theVerts
                       --make sure only unique faces are written to the array
                       for f in theFaces where findItem face_array f == 0 do
                           append face_array f
                 )--end while cnt --once all connected faces in an element are collected, --create a new empty EMesh:
                 with undo on
                 new_emesh = Editable_mesh()
                 --detach the collected faces and assign to the EMesh's TriMesh
                 new_emesh.mesh = meshop.detachFaces obj face_array delete:true asMesh:true
                 --Copy the transformation of the original object
                 new_emesh.transform = mesh.transform
                 --Assign a unique name based on the original one
                 new_emesh.name = uniquename (mesh.name +"_UVsplit")
           )--end while numfaces
       delete obj--delete the clone which has no faces at this point
       )
   )

   --Example usage:
   theTeapot = Teapot mapcoords:true
   splitMeshByUVElements theTeapot 1