Assuming a group action $A \times V \rightarrow{A}$ to set an affine space $A$, and assuming that the space $V$ is a translation-space, that is a vector space; then, is a projective reference needed (beforehand) in order to turn points into vectors on a given coordinate within the quotient space (projective space) and allowing to take subspaces' (hyperplanes') translations?
Thanks you in advance.