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Thread: Matrix libs in as3?

  1. #1
    Senior Member realMakc's Avatar
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    Matrix libs in as3?

    We all know that each and every flash 3D engine comes with 4x4 matrix math code (and sometimes 3x3 operations included), but recently I ran into a problem solving equation involving 4x3 (and, obviously 3x4) matrices at runtime. Having no suitable code at hand, I resorted to mathcad symbolic solution in terms of numbers that make up these matrices; needless to say, implementing these expressions is not fun. So. Does anyone know solid matrix math library for as3 that can operate with matrices of any dimensions?
    who is this? a word of friendly advice: FFS stop using AS2

  2. #2
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    You can try this. I don't seem to remember ever testing it, so don't assume everything works! It's Flash 10

    http://lab.generalrelativity.org/file/MatrixND.as

    EDIT: Meh, looked at it, looks like it only has square matrix solvers...
    Last edited by newblack; 06-11-2009 at 08:28 AM.

  3. #3
    Senior Member realMakc's Avatar
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    Interestingly enough, top google hits for non-square matrix inverse all say that there is no inverse for non-square matrices, and one should resort to LS/QR/SVD. If that's really so, I am puzzled how mathcad was able to find exact solution of my problem. Maybe I had a typo somewhere, but we'll see once I will implement it.
    who is this? a word of friendly advice: FFS stop using AS2

  4. #4
    Senior Member realMakc's Avatar
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    Yep, that was a typo, I missed few variables, hence no solution for me
    who is this? a word of friendly advice: FFS stop using AS2

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    that sucks... what are you trying to solve?

  6. #6
    Senior Member realMakc's Avatar
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    if you have to ask I was trying to solve for 3d coords from 2d coords of 3 points for sort of augmented reality experiment (but without flartoolkit), and I missed how their z-s remained in what I thought was solution, so I had to estimate z-s in some other way (I had some limited success here btw). I've found some article on homography that said it takes at least 4 points, which brings us back to 4x4 matrices, I guess, and more than 4 points naturally go with LS.
    Last edited by realMakc; 06-12-2009 at 05:52 PM.
    who is this? a word of friendly advice: FFS stop using AS2

  7. #7
    Senior Member realMakc's Avatar
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    Quote Originally Posted by newblack View Post
    I don't seem to remember ever testing it, so don't assume everything works!
    I finally got back to this, and tested, and there's actually a bug or restriction of some sort in the code. Check it out here (scroll down to line 107), let me know what you think...
    Last edited by realMakc; 09-08-2010 at 10:53 PM.
    who is this? a word of friendly advice: FFS stop using AS2

  8. #8
    Senior Member realMakc's Avatar
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    duhh, found the answer here:
    If the matrix A is positive definite symmetric or if the matrix is diagonally dominant, then pivoting is not necessary; otherwise the version using pivoting should be used.
    looks like I need to edit your code a bit more
    who is this? a word of friendly advice: FFS stop using AS2

  9. #9
    Actionscript Developer KigD's Avatar
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    Actionscript 3 Matrix Library

    Here's an Actionscript 3 Matrix Library:
    http://k2xl.com/wordpress/2010/12/27...atrix-library/

    Direct link to library: http://code.google.com/as3matrix/
    K2xL - My games, tutorials, message boards, and experiments.
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  10. #10
    Senior Member realMakc's Avatar
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    who is this? a word of friendly advice: FFS stop using AS2

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