1. A method for perceiving material bodies, which is intended to locate said bodies on an at least 2-dimensional occupancy grid G, having a first resolution stepsize R G , and comprising a set of cells represented by vertices and segments connecting these vertices, the method using a sensor for detecting obstacles which is positioned at a source point S, said method comprising: Acquisition by said sensor of a measurement of the position of a material body detected at a point F; Definition of the coordinates of the points S and F in a space discretized with the aid of a spatial stepsize δ, the spatial stepsize δ being smaller than the resolution stepsize R G of the grid G, the size of the cells being defined by size (c)=r·δ, r ∈ , a point M with coordinates (l,m) in this discretized space being situated in the continuous space at the point (x,y), where 
 x=l·δ 
 y=m ·δ the points S and F having respectively coordinates (l S , m S ) and (l F , m F ); Determination of the cell c s of the occupancy grid G containing the point S; Determination of the coordinates, in the discretized space, of an initial vertex V0 of the cell c s ; Computation of the value of an, integer, error parameter E by using an error function Err d (M) making it possible to evaluate, in the discretized space, an offset between a point of the space and a straight line connecting the points S and F, said error parameter E being initialized to the value taken by said error function for said initial vertex V0 of the cell c s , Computation of the value of said error parameter E for at least one first vertex V1 i of the current cell c i of the grid in the course of observation, corresponding to Err d (V1 i ), this computation consisting in carrying out an addition or subtraction operation between integer numbers, between on the one hand said value of the parameter E, obtained for the initial vertex V0 i of the current cell c i , and corresponding to Err d (V0 i ), and on the other hand an integer increment value (Δ) predefined as a function of the coordinates of the points S and F in the discretized space, Studying the previously computed value of the error parameter E with respect to a reference value and determining a following cell c i+1 situated in proximity to the path [SF]; Computing, if necessary, the value of said error parameter E for an initial vertex V0 i+1 of the following cell c i+1 , corresponding to Err d (V0 i+1 ), this computation consisting in carrying out an addition or subtraction operation between integer numbers, between on the one hand said value of the parameter E, obtained for at least one vertex V i of the current cell c i , and corresponding to Err d (V i ), and on the other hand an integer increment value (Δ) predefined as a function of the coordinates of the points S and F in the discretized space, Using this following cell c i+1 and said value of the error parameter E, obtained for said initial vertex V0 i+1 of this cell, as starting point and repeating steps f to h until at least the cell c F containing the final point F is reached, Determining the list {c i } of cells considered in the previous steps and situated on the path [SF] or situated a predefined distance from the path [SF] and updating said occupancy grid G for the listed cells.