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