Creation of pointcloud cycles many times over the points

[paskino]

Because these loops are in Python they are extremely slow, especially for large clouds

[paskino]

One such loop is

iDVC/src/idvc/pointcloud_conversion.py

Lines 251 to 274 in a14a893

	while n_b < max_b:
	n_c = offset[1]
	while n_c < max_c:
	b = (n_b / max_b) * image_spacing[0] * image_dimensions[0] #- image_origin[0] #+ int(image_dimensions[0] * density[0] * .7)
	c = (n_c / max_c) * image_spacing[1] * image_dimensions[1]# - image_origin[1] #+ int(image_dimensions[1] * density[1] * .7)
	if self.GetOrientation() == 0: #YZ
	vtkPointCloud.InsertNextPoint( a, b, c)
	# print(c)
	elif self.GetOrientation() == 1: #XZ
	vtkPointCloud.InsertNextPoint( b, a, c)
	# print(c)
	elif self.GetOrientation() == 2: #XY
	vtkPointCloud.InsertNextPoint( b, c, a)
	# print(a)
	n_c += 1
	n_b += 1
	self.UpdateProgress((n_c + max_b * n_b ) / tot)

which may benefit using https://docs.python.org/3/library/itertools.html#itertools.product