immersive flythrough

• To: visad-list@xxxxxxxxxxxxx
• Subject: immersive flythrough
• From: Doug Lindholm <lind@xxxxxxxx>
• Date: Fri, 12 Mar 1999 11:20:48 -0700

Hi,

I'd like to define a trajectory through 3D space and visualize the scene
(with 3D terrain, wind vectors, clouds...) from the perspective of an
observer moving along that trajectory. A hint from Bill via Steve
suggested ProjectionControl.setMatrix.

Am I correct in assuming that the nature of that matrix is that of
javax.vecmath.Matrix4d? I was able to rotate the display using
Matrix4d.rotX (with the side effect of zooming in also) but the display
returned to its default orientation as soon as I clicked on it with the
mouse.

What exactly is the nature of this matrix? How would you recommend
modifying the matrix to effect a rotation, translation, or zoom? In
other words, how can I programmatically control the same effects that
are already tied to the mouse?

Here's the method I'm testing with:

  public static void doRotation(DisplayImpl display)
       throws Exception
  {
    ProjectionControlJ3D pc = new ProjectionControlJ3D(display);
    double[] m = pc.getMatrix();
    Matrix4d matrix = new Matrix4d(m);
    double angle = 1.0;
    matrix.rotX(angle);
    // there ought to be a Matrix4d method to do this?
    int k = 0;
    for(int row=0;row<4;row++){
      for(int col=0;col<4;col++){
        m[k++] = matrix.getElement(row,col);
      }
    }
    pc.setMatrix(m);
  }


Thanks,
Doug

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| Doug Lindholm, Software Engineer          |  E-mail: lind@xxxxxxxx   |
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