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Moving point along plane

Discussion in 'Mathematics and Physics' started by dougy83, Sep 15, 2014.

  1. dougy83

    dougy83 Well-Known Member

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    Hi,

    Given a point p (having a direction n), I want to move it perpendicular to n until p'+dn = (0,0,0). What the best way to calculate the distance d?

    I thought this would be quite simple, but unfortunately I'm feeling quite simple today.

    Thanks for any help.
     
    Last edited: Sep 16, 2014
  2. dougy83

    dougy83 Well-Known Member

    Joined:
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    Location:
    Brisbane, Australia
    Ok, it is pretty simple, just having a slow day.
    First n is rotated to be (0,1,0) {could have been parallel to any axes} using rotation matrix A.
    Point p is then rotated around (0,0,0) using the same matrix to become p'.
    The x & z components of p' are set to zero to become p", which now lies on the y axis. The distance to p" is simply the y component of p' (or p").
     

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