anchor.diff:  
   
   [.right]
  -image::glass-teapot1.png[glass-teapot1.png,width="160",height="90"]
  +image::intermediate/glass-teapot1.png[glass-teapot1.png,width="160",height="90"]
   
   
   Environment Mapping or Reflection Mapping is used to create the impression of reflections and refractions in real time. It's faster (but less accurate) than the raytracing methods used in offline rendering applications.
  
positive.code: 
  
  [.right]
  image::blenderswordsman.png[blenderswordsman.png,width="195",height="151"]
  
  
  An animated character has an armature: An internal skeleton (Bones) and an external surface (Skin). The Skin is the visible outside of the character and it includes clothing. The Bones are not visible and are used to interpolate (calculate) the morphing steps of the skin.
  
negative.code: ==== Surface Normal Vectors
  
  [.right]
  image::intermediate/300px-surface_normal.png[300px-surface_normal.png,width="",height=""]
  
  A surface normal is a vector that is perpendicular (orthogonal) to a plane.
  You calculate the Surface Normal by calculating the cross product.
  