How do I Split a Mesh by UV Elements?

MAXScript FAQ > Working With Editable Meshes > 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

How do I Split a Mesh by UV Elements?

See Also