in reply to Re^2: (OT) moving points from one plane to another
in thread (OT) moving points from one plane to another

Giving it some extra thought and reading again through the other responses I think your best bet is to follow BrowserUK's advice. Let me add that the angle between two planes is given by the angle between the normal vectors. See Lines and Planes for some basic examples. You can use the rotation matrices as described in the paper (the link you provided yourself) or look them up in Wikipedia or Mathworld.

It's a pity you don't describe what problem your working on. A physics problem? Computer graphics? etc.

  • Comment on Re^3: (OT) moving points from one plane to another

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Re^4: (OT) moving points from one plane to another
by merrymonk (Hermit) on Jul 09, 2009 at 12:52 UTC
    It is a part geometry problem where the basic profile is defined in one plane but is used in another plane.
    Do you know if I am correct in thinking that the angle between the two planes is the dot product of the normals to the two planes?
[reply]
      the angle between the two planes is the dot product of the normals to the two planes?

      Correct.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

      No!

      The angle between the normals is the angle between the two planes, but you don't get angles out of a dot product!

      If θ is the angle between the planes: θ = cos-1((n1.n2)/(|n1||n2|))

      This formula is based on one of the definitions of the dot product, which states: n1.n2=|n1||n2|cos(θ)

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