In this paper, we construct solutions to the Kadomtsev-Petviashvili equation (KPI) by using a Darboux transformation with particular genera-ting functions limited to one degree of summation. With this choice, we get rational solutions expressed in terms of a wronskian of order N depending on N(D+5) real parameters. In this case, we construct explicitly multi-parametric rational solutions to the KPI equation and we study the patterns of their modulus in the plane $(x,y)$ and their evolution according to time and parameters.