public void pan_lr(double amount)
{
// move cen to the left
Vector v = up.Cross(eye - cen);
v.normalize();
amount = 0.001 * amount * _r;
cen.x += amount * v.x;
cen.y += amount * v.y;
cen.z += amount * v.z;
recalc();
}
private void recalc()
{
// recalculate eye position
eye.x = cen.x + _r * Math.Cos(_theta) * Math.Sin(_fi);
eye.y = cen.y + _r * Math.Sin(_theta) * Math.Sin(_fi);
eye.z = cen.z + _r * Math.Cos(_fi);
// recalculate up-vector
Vector n = new Vector(Math.Sin(_theta), -Math.Cos(_theta), 0);
up = n.Cross(eye - cen);
up.normalize();
// System.Console.WriteLine("Camera: cen=" + cen + " eye=" + eye);
}
