Re: Projection matrix from two points

Java 3D comes with the javax.vecmath package which has lots of matrix manipulation methods.

http://java.sun.com/products/java-media/3D/forDevelopers/J3D_1_3_API/j3dapi/index.html

Doug

Bill Hibbard wrote:
Hi Jeff,


We're playing around with flythroughs in the IDV and I am trying to figure
out (I am particularly brain dead trying to think in 3D) how to
create a projection matrix from two points, (x1,y1,z1) (x2,y2,z2)
such that the camera position is at the first point and the point of view
is towards the second point.

Any ideas?


Yeah, this stuff is a mess. Check out the article at:

  http://www.makegames.com/3drotation/

If you scroll down to "The Problem", there is an example
of building a matrix if you are standing at the point
(-1, 0, 1) and facing the point (-2, 0, 2). Note VisAD
includes some simple matrix manipulation methods in
visad/java3d/MouseBehaviorJ3D.java that may be useful.

Please let us know if this continues to be a problem.

Good luck,
Bill

--
*----------------------------------------------------------------------*
| Doug Lindholm, Software Engineer          |  E-mail: lind@xxxxxxxx   |
| Unidata Program Center                    |   Phone: 303-497-8659    |
| UCAR Office of Programs                   |                          |
| P.O. Box 3000                             |     There's no place     |
| Boulder, Colorado 80307-3000              |        like $HOME        |
*----------------------------------------------------------------------*