The position of the wand within the magnetic field calculated by the board is updated in real time. The user adds a point (typically) by clicking a foot pedal.

Advantages:

• Concave and topologically complex surfaces are no problem
  
  
• User has control over mesh density and exact point placement
  
  

Disadvantages

• Large objects won't fit on the board
  
  
• Metal objects disrupt the magnetic field
  
  

  Sensitive to distortion from electronic equipment (your monitor!)
  
  

• Inaccurate (1/32")