Thanks for those links.. and have had a quick read. I think the FAQ
covers all the matrices I need!

Just one further quick question given that this (taken from the FAQ) is
the final matrix I need:

         |  CE      -CF       D   0 |
    M  = |  BDE+AF  -BDF+AE  -BC  0 |
         | -ADE+BF   ADF+BE   AC  0 |
         |  0        0        0   1 |

I presume this would be a Quaternion Quat4d / Quat4f in java3d
Is this equivalent to the following Matrix3d/Matrix3f

         |  CE      -CF       D  |
   MM  = |  BDE+AF  -BDF+AE  -BC |
         | -ADE+BF   ADF+BE   AC |

Thanks again
Spencer Goh
~~~~~~~~~~~~~~~~~~~~~~~~
Postgraduate
Computer Science
University of Birmingham
07747 600 436
www.spencergoh.com
[EMAIL PROTECTED]


-----Original Message-----
Sent: 29 August 2001 20:48

Also see:
http://www.cs.ualberta.ca/~andreas/math/matrfaq_latest.html
http://www.ddj.com/articles/2001/0165/0165f/0165f.htm
http://www.flipcode.com/geometry/

        Dave

> -----Original Message-----
> From: Kevin Williams [SMTP:[EMAIL PROTECTED]]
> Sent: Wednesday, August 29, 2001 1:29 PM
>
> Use 2 transforms, one to translate and one to do the rotation.  Then
you
> can use the rotX, rotY, rotZ. Also every time you move the object, you
> don't have to also rotate it (the rotation stays the same).
>
> Kevin
>
> -----Original Message-----
> Sent: Wednesday, August 29, 2001 10:54 AM
>
>       Could anyone point me to a website which explains the matrix
> transforms for rotations. I need to do various rotations about a
point,
> not necessarily the origin.  At the moment I'm computing them by hand
> using standard trig equations but I'm certain there is a nice neat was
of
> putting it all into a Matrix but I just can't remember how (Rusty on
the
> old matrix maths !  :-)
>
>       transform.setRotation(Matrix3f)
>       { a1, a2, a3
>         b1, b2, b3
>         c1, c2, c3
>       }
>
>       if anyonen could tell me what I have to put in those fields..
eg..
> to get a rotation about the X-axis by n degrees about the point by
m(xx,
> yy, zz) etc etc  just the whole load of them..
>
>       As I said, I currently use a load of sines and cosines to
calculate
> it myself.. but then I'm stuck cos I can't use rotX rotY rotZ because
the
> reset the other transforms and I can't figure out how to use
> setRotation...
>
>       Any explainations of how to use the rotation matrix or pointers
to
> web resources appreciated.
>
>       Thanks
>       Spencer Goh

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