System or components such as software for 3D modelling of bodies is described. This can be realized by a computer based method for modelling a body by scanning a determined space divided into elementary spaces, each elementary space being assigned a signed distance parameter indicative of the distance of said elementary space to said body and a weight parameter indicative of the importance of the distance parameter; said scanning of said body providing scanned points and each scanned point thus obtained possibly modifying said signed distance and weight parameters of each elementary space of said determined space; wherein, each one of selected elementary spaces is modified by subdividing said selected elementary space into higher level elementary spaces defined by the same parameters; wherein, in order to decrease details of the model of said body, said elementary spaces are modified by replacing selected elementary spaces with lower level elementary spaces.