Patent ID: 8676546

Claim:
A computer implemented method for creating a flow-grade solution comprising: (a) defining, in a computer, in a computer-aided design (CAD) building information modeling (BIM) application, a curve from which a slope is to be projected; (b) creating in the computer, a first field depth buffer comprising a two-dimensional (2D) array with one element for each (x-y) coordinate in the 2D array; (c) specifying in the computer, a slope angle for the slope; (d) rendering in the computer, one or more grading shapes by sweeping a cone with the slope angle along the curve; (e) as the one or more grading shapes are rendered, using a grid to capture in the computer, into the first field depth buffer, an elevation for each vertex of the grid; and (f) obtaining in the computer, a flow grade solution represented by the first field depth buffer, wherein: (i) the flow grade solution represents an approximate geometry of the slope projected from the curve; (ii) the flow grade solution comprises a path of steepest slope from any given location in the grid; (iii) a steepest slope angle of the steepest slope is equal to the slope angle specified; and (iv) the path of steepest slope from any given location in the grid is determined by: (1) computing one or more contours by interpolating elevations stored for each vertex of the grid in the first field depth buffer; and (2) following a perpendicular path that is perpendicular to the one or more contours from the given location in the grid.