title: vPython does not import
body: <p>I've installed vPython 7 on my Linux machine running Mint 18.2 64. Using the iPython environment and Python 2.7.12 I receive the following traceback when trying to import visual. </p>
  
  <pre><code>In [1]: from visual import *
  ---------------------------------------------------------------------------
  ValueError                                Traceback (most recent call last)
  &lt;ipython-input-1-96658a14bb68&gt; in &lt;module&gt;()
  ----&gt; 1 from visual import *
  
  /usr/lib/python2.7/dist-packages/visual/__init__.pyc in &lt;module&gt;()
      64                                frame, pyramid, ellipsoid, curve, faces, convex, helix,
      65                                points, distant_light, local_light)
  ---&gt; 66 from visual.ui import display
       67 import materials
       68 
  
  /usr/lib/python2.7/dist-packages/visual/ui.py in &lt;module&gt;()
        1 import cvisual
        2 from primitives import distant_light, local_light
  ----&gt; 3 import materials
        4 
        5 # Code to provide special initialization for a display object, and overloaded
  
  /usr/lib/python2.7/dist-packages/visual/materials.py in &lt;module&gt;()
      150 texturePath = os.path.split( __file__ )[0] + "/"
      151 data = loadTGA(texturePath+"turbulence3") # the targa file is 512*512*3
  --&gt; 152 tx_turb3 = raw_texture( data=reshape(data,(64,64,64,3)), interpolate=True, mipmap=False )
      153 tx_wood = raw_texture( data=loadTGA(texturePath+"wood"), interpolate=True)
      154 
  
  /usr/lib/python2.7/dist-packages/visual/materials.py in __init__(self, **kwargs)
       68         cvisual.texture.__init__(self)
       69         for key, value in kwargs.iteritems():
  ---&gt; 70             self.__setattr__(key, value)
       71 
       72 class shader_material(cvisual.material):
  
  ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()
  </code></pre>
  
  <p>I am not sure why the package refuses to import properly. Anyone seen this error before and know the cause?</p>