   calculating reflection matrix
  I''ve got a question: how to calculate the reflection matrix for a plane if I know the  equation of the plane and the position of the object to reflect? 
  I don''t know the answer to the specific question, but the vector V reflected on a plane with normal N produces "V - 2 * (V dot N) * N".I think. I don''t have my source to hand, so it may be slightly out of order. Easy to test it though. Best viewed with irony.Hail Eris! All fnord hail Discordia! 