klasa diament

    class diament
    {
        private Punkt[] rogi = new Punkt[4];
        private double bok = 0.8;
        private Brush b;
        private Pen p;

        public diament(Punkt p0, Color k1, Color k2)
        {

            double b2 = bok / Math.Sqrt(2);
            rogi[0] = new Punkt(p0.x, p0.y + b2, p0.z + b2);
            rogi[1] = new Punkt(p0.x, p0.y + b2, p0.z - b2);
            rogi[2] = new Punkt(p0.x, p0.y - b2, p0.z - b2);
            rogi[3] = new Punkt(p0.x, p0.y - b2, p0.z + b2);
            b = new SolidBrush(k1);
            p = new Pen(k2);
        }

        public void rysuj(Graphics g, ref T3d projektor)
        {
            Point[] points = new Point[4];
            int[] xe = new int[4];
            int[] ye = new int[4];

            for (int i = 0; i < 4; ++i)
            {
                projektor.punkt_3d(out xe[i], out ye[i], rogi[i]);
                points[i].X = xe[i];
                points[i].Y = ye[i];
            }

            g.FillPolygon(b, points);
            g.DrawPolygon(p, points);
        }

    }


konstruktor
diament d1 = new diament(new Punkt(0, 0, 0), Color.Black, Color.White);

rysuj
po tej linijce
T3d projektor = new T3d(obserwator,0,0,szer,wys,0.5,0,0);
to
 d1.rysuj(g, ref projektor);