Uh you don't really need matrices. Here is example of drawing a tilted polygon.
PHP Code:
with (findimg(200)) {
layer = 4;
dimension = 3;
polygon = {
50, 50, 0,
600, 50, 0,
600, 600, 200,
50, 600, 200
};
image = "map.png";
mode = 0;
alpha = 0.75;
red = 1;
green = 1;
blue = 1;
}