(PHP 4 >= 4.0.1, PECL)
The swf_ortho() function defines an orthographic mapping of user coordinates onto the current viewport.
swf_ortho() creates a 3D-matrix; In most cases you'll only need swf_ortho2() to create a 2D-Matrix. But you should know what's possible with a 3D-matrix: so jump to swf_lookat() and check out an 3D-example