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 CAD / Ray-Tracing / *2772 (-5)
  Re: Inverse matrix?
 
(...) I just realised something... do you want a general inverse or a specific inverse? Some inversions are simple eg. a pure rotation can be inverted by taking its transpose and reflections are their own inverses. Tim (17 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
 
  Re: Inverse matrix?
 
(...) There really is no easy way to do it. Feel free to look at TCVector::invertMatrix in the LDView code if you want to see code that does it on a 4x4 matrix. To convert a 3x3 matrix into a 4x4 matrix, put the 3x3 in the top left, put a 1 in the (...) (17 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
 
  Re: Inverse matrix?
 
(...) The inverse of <1,0,0,0,1,0,0,0,1,0,0,0> is itself. To compute the inverse of a general 3x3 matrix (essentially what you need to do) is rather complicated. You could do it in a macro using Gaussian elimination [1]. Tim [1] (URL) (17 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
 
  Inverse matrix?
 
Does anyone know how to generate an inverse matrix. By inverse I mean it will undo the rotation of the original matrix. I thought the inverse of <1,0,0,0,1,0,0,0,1,0,0,0> was <-1,0,0,0,-1,0,0,0,-1,0,0,0>. In other words, multiply every value by -1. (...) (17 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
 
  Re: A question about an animation scene
 
(...) You are not specifying a custom clock value so your spline lasts from frames 1 to 121. You actually want to specify a custom clock value. Something like this: animate_by_spline (east_to_south, auto_banking (0) + spline_clock ( ..... ) )} The (...) (17 years ago, 6-Apr-07, to lugnet.cad.ray)


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