Method referenceSplit

test/IECoreScene/MeshAlgoSplitTest.py:145–254

( self, mesh, primVarName )

	# the algorithm to start with, it ensures that the results do not change, and that any optimizations which
	# use indices do not affect the final result.
	def referenceSplit( self, mesh, primVarName ):
		faceCounts = []

		remaps = {}
		pvData = mesh[primVarName].expandedData()
		for i in range( len( pvData ) ):
			remaps.setdefault( str( pvData[i] ), (pvData[i], []) )[1].append( i )

		# \todo Replace with itertools.accumulate once we're on Python 3
		def accumulateInPython2( iterable ):
			it = iter( iterable )
			try:
				total = next( it )
			except StopIteration:
				return
			yield total
			for element in it:
				total += element
				yield total

		faceIndices = [0] + list( accumulateInPython2( mesh.verticesPerFace ) )[:-1]

		result = []
		for key, r in sorted( remaps.values() ):
			reindex = {}
			newVerticesPerFace = []
			newVertIndices = []
			mapFaceVert = []

			usedIndices = set()
			for i in r:
				vpf = mesh.verticesPerFace[i]
				newVerticesPerFace.append( vpf )
				for j in range( vpf ):
					origFaceVert = faceIndices[i] + j
					origVert = mesh.vertexIds[ origFaceVert ]

					usedIndices.add( origVert )

			usedIndices = sorted( usedIndices )

			for i in range( len( usedIndices ) ):
				reindex[ usedIndices[i] ] = i

			for i in r:
				vpf = mesh.verticesPerFace[i]
				for j in range( vpf ):
					origFaceVert = faceIndices[i] + j
					origVert = mesh.vertexIds[ origFaceVert ]

					newIndex = usedIndices.index( origVert )
					newVertIndices.append( newIndex )
					mapFaceVert.append( origFaceVert )

			rMesh = IECoreScene.MeshPrimitive(
				IECore.IntVectorData( newVerticesPerFace ),
				IECore.IntVectorData( newVertIndices ),
				mesh.interpolation