I am having a hard time understanding how to convert from projective coordinates, back to affine.
I am trying to compute point addition for Edward curves. Say we have the following: $$\begin{align} x_i &= X_i/Z_i\\ y_i &= Y_i/Z_i\\ A &= Z_1*Z_2\\ B &= A^2\\ C &= X_1*X_2 \\ D &= Y_1*Y_2 \\ E &= d*C*D\\ F &= B-E\\ G &= B+E\\ X_3 &= A* F*((X_1+Y_1)*(X_2+Y_2)-C-D)\\ Y_3 &= A* G*(D-C)\\ Z_3 &= c* F*G\\ \end{align}$$
[Editor's note: equations match hyperelliptic.org's add-2007-bl]
Now after obtaining values for $X_3$ and $Y_3$, to get back to affine coordinates, would I have to compute $X_3/Z_3$ and $Y_3/Z_3$ to get $(x_3,y_3)$ ?