Re: Projection matrix from two points

• To: Jeff McWhirter <jeffmc@xxxxxxxxxxxxxxxx>
• Subject: Re: Projection matrix from two points
• From: Bill Hibbard <billh@xxxxxxxxxxxxx>
• Date: Thu, 10 Feb 2005 12:57:12 -0600 (CST)

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

• Follow-Ups:
  • Re: Projection matrix from two points
    • From: Doug Lindholm

• References:
  • Projection matrix from two points
    • From: Jeff McWhirter