Some questions to ask yourself as you go :

• Do you understand each of the problems in terms of the form•Z representation? Remember that a
  properly formed form•Z solid must be a 2-manifold, must be planar, must have a complete
  boundary and must be oriented so that its faces point outwards.
  
• Do you understand how form•Z controls things such as shadows? Typically, control is distributed
  amongst all the objects involved. For example, for a shadow to be cast, the casting object must
  be set to cast shadows, the receiving object to receive them, the light to cast shadows and the
  rendering engine to render shadows.
  
• Have you a generic plan for sorting out bugs?
  
• Can you relate each of the bugs to one or more of the Elements of Computer Work from the
  lecture series?