public Point3[] CircleCoordinates(float y)
{
Point3[] pts = new Point3[30];
var m = new Matrix3 ();
for (int i = 0; i < pts.Length; i++)
pts [i] = m.Cylindrical (r, i * 360 / (pts.Length - 1), y);
return pts;
}
public Point3 Cylindrical(float r, float theta, float y)
{
var pt = new Point3 ();
var sn = (float)Math.Sin(theta * Math.PI / 180);
var cn = (float)Math.Cos(theta * Math.PI / 180);
pt.X = r * cn;
pt.Y = y;
pt.Z = -r * sn;
pt.W = 1;
return pt;
}