Computer-implemented method for designing a three dimensional model of an object suited to be produced by means of a stereolithography process, comprising the following steps: - drawing a three-dimensional model of said object; - defining points of development of supporting elements on the model of said object; - generating supporting elements at the level of said points of development; - subdividing said three-dimensional model of said object with the supporting elements into a plurality of parallel layers having a predefined thickness; - transferring the resulting digital data related to the three dimensional model of said object with the supporting elements to a stereo-lithographic machine for production, wherein the step of defining points of development of supporting elements on the model of said object includes the following steps: - defining the surfaces of said object or portion of surfaces whose points are oriented towards a reference plane; - tracing a predefined grid of points on each one of said surfaces or portions of said surfaces; - defining, for each one of said surfaces or portions of said surfaces, the local minimum points with respect to said reference plane, for each one of said surfaces or portions, in the case where at least one of said local minimum point has been identified, adapting said grid of points so that one of said points of said grid of points substantially coincides with each one of said local minimum points; - for each one of said surfaces or portion of said surfaces, identifying the points of said adapted grid of points as points of development of supporting elements of said object, characterized in that said step of adaptation of said grid of points includes: the modification of the position of the point of said grid that is geometrically nearest to said local minimum point in such a way that said nearest point substantially coincides with said local minimum point, or the modification of the position of at least one of the lines of points (34; 35) comprising said point that is nearest to said local minimum point, in such a way that said nearest point substantially coincides with said local minimum point. - drawing a three-dimensional model of said object; - defining points of development of supporting elements on the model of said object; - generating supporting elements at the level of said points of development; - subdividing said three-dimensional model of said object with the supporting elements into a plurality of parallel layers having a predefined thickness; - transferring the resulting digital data related to the three dimensional model of said object with the supporting elements to a stereo-lithographic machine for production, wherein the step of defining points of development of supporting elements on the model of said object includes the following steps: - defining the surfaces of said object or portion of surfaces whose points are oriented towards a reference plane; - tracing a predefined grid of points on each one of said surfaces or portions of said surfaces; - defining, for each one of said surfaces or portions of said surfaces, the local minimum points with respect to said reference plane, - defining the surfaces of said object or portion of surfaces whose points are oriented towards a reference plane; - tracing a predefined grid of points on each one of said surfaces or portions of said surfaces; - defining, for each one of said surfaces or portions of said surfaces, the local minimum points with respect to said reference plane, for each one of said surfaces or portions, in the case where at least one of said local minimum point has been identified, adapting said grid of points so that one of said points of said grid of points substantially coincides with each one of said local minimum points; - for each one of said surfaces or portion of said surfaces, identifying the points of said adapted grid of points as points of development of supporting elements of said object, - for each one of said surfaces or portion of said surfaces, identifying the points of said adapted grid of points as points of development of supporting elements of said object, characterized in that said step of adaptation of said grid of points includes: the modification of the position of the point of said grid that is geometrically nearest to said local minimum point in such a way that said nearest point substantially coincides with said local minimum point, or the modification of the position of at least one of the lines of points (34; 35) comprising said point that is nearest to said local minimum point, in such a way that said nearest point substantially coincides with said local minimum point. the modification of the position of the point of said grid that is geometrically nearest to said local minimum point in such a way that said nearest point substantially coincides with said local minimum point, or the modification of the position of at least one of the lines of points (34; 35) comprising said point that is nearest to said local minimum point, in such a way that said nearest point substantially coincides with said local minimum point.