To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cad.rayOpen lugnet.cad.ray in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / Ray-Tracing / 2771
2770  |  2772
Subject: 
Re: Inverse matrix?
Newsgroups: 
lugnet.cad.ray, lugnet.cad
Date: 
Sat, 7 Apr 2007 22:18:16 GMT
Viewed: 
6789 times
  
In lugnet.cad.ray, James Reynolds wrote:
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.

I know POV-Ray 3.6 has an inverse matrix function but it doesn't work in 3.1,
which is what I'm using.

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 bottom right, and fill in the other empty cells with 0.

--Travis



Message has 1 Reply:
  Re: Inverse matrix?
 
(...) Hehehe, cool, I'll try that. Thanks! James (18 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)

Message is in Reply To:
  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. (...) (18 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)

13 Messages in This Thread:



Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact

This Message and its Replies on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

Custom Search

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR