internal void update()
{
Vector diff = new Vector(position, lookAt);
this.direction = -diff.normalize();
this.right = new Vector(0, 1, 0).cross(direction).normalize();
this.down = -right.cross(direction);
}
public Plane(Vector normal, double distance, Color color)
{
this.distance = distance;
this.normal = normal.normalize();
this.color = color;
}