Plot ellipsoids with Mayavi

Hi. I wanted to plot 3D ellipsoids with Mayavi. I got the following script
```
from enthought.mayavi.api import Engine
from enthought.mayavi.sources.api import ParametricSurface
from enthought.mayavi.modules.api import Surface
from enthought.mayavi import mlab

import numpy as np

engine = Engine()
engine.start()
scene = engine.new_scene()
scene.scene.disable_render = True # for speed

surfaces = []
for i in range(10):

source = ParametricSurface()
source.function = 'ellipsoid'
engine.add_source(source)

surface = Surface()
source.add_module(surface)

actor = surface.actor # mayavi actor, actor.actor is tvtk actor
#actor.property.ambient = 1 # defaults to 0 for some reason, ah don't need it, turn off scalar visibility instead
actor.property.opacity = 0.5
actor.property.color = tuple(np.random.rand(3))
actor.mapper.scalar_visibility = False # don't colour ellipses by their scalar indices into colour map
actor.property.backface_culling = True # gets rid of weird rendering artifact when opacity is < 1
#actor.property.frontface_culling = True
actor.actor.orientation = np.random.rand(3) * 360 # in degrees
actor.actor.origin = np.random.rand(3)
actor.actor.position = np.random.rand(3)
actor.actor.scale = np.random.rand(3)

surfaces.append(surface)

scene.scene.disable_render = False # now turn it on

# set the scalars, this has to be done some indeterminate amount of time
# after each surface is created, otherwise the scalars get overwritten
# later by their default of 1.0
for i, surface in enumerate(surfaces):
vtk_srcs = mlab.pipeline.get_vtk_src(surface)
print('len(vtk_srcs) = %d' % len(vtk_srcs))
vtk_src = vtk_srcs[0]
try: npoints = len(vtk_src.point_data.scalars)
except TypeError:
print('hit the TypeError on surface i=%d' % i)
npoints = 2500
vtk_src.point_data.scalars = np.tile(i, npoints)

# on pick, find the ellipsoid with origin closest to the picked coord,
# then check if that coord falls within that nearest ellipsoid, and if
# so, print out the ellispoid id, or pop it up in a tooltip

mlab.show()

```

I found that I cannot visualize my ellipsoids with this script, because I do not understand the meaning of some commands/functions.

My data included: the center of ellipsoids, vectors of three principal axes, and the lengths of three axes.

But, as one can see in the script, the input parameters of the script are
```
actor.actor.orientation = np.random.rand(3) * 360 # in degrees
actor.actor.origin = np.random.rand(3)
actor.actor.position = np.random.rand(3)
actor.actor.scale = np.random.rand(3)
```
The `origin` might be the center of ellipsoids. But I do not understand `orientation`, `position`, and 'scale'?

How can I generate my ellipsoids with these functions? Can someone help me? thanks in advance.