public Camera(Point3 location = null, Point3 look_at = null, float bumps = 0.0f, Signal<float> bumpsr = null, String mesh = null, Signal<String> meshr = null, bool reactive = false)
{
//to add a mesh to the camera use the mesh identifier in the constructor
//to make the image appear as if through curved glass increase the number of bumps
this.location = location ?? new Point3(0, 2, -3, reactive: reactive);
this.look_at = look_at ?? new Point3(0, 1, 2, reactive: reactive);
_bumps = bumpsr ?? new Lift0f(bumps);
_mesh = meshr ?? new Lift0s(mesh);
this.reactive = reactive;
}