A user of a modeling application modifies an initial virtual object using a sketch drawn on one or more construction planes. The targeting set assembly comprises a needle assembly, which comprises a connecting member. The receiver assembly includes an analyzer for polarimetrically processing the signal, including differencing the signal to generate a difference electric field proportional to the difference of the sample and reference electric fields. The secret code is periodically scrambled so that play participants must act quickly and cooperate with one another to determine and enter the correct code.