Systems and methods of retopologizing graphical data

Abstract

Systems and methods of updating graphical objects are disclosed. The methods and systems receive polygonal data which describe discrete points on an object. A user gives an indication, and retopologized data for a region is automatically generated based on the indication such that the retopologized data has fewer geometries than the received polygonal data in the region.

What is claimed is: 
     
         1 . A method of producing an electronic geometric model with a computer system, the method comprising:
 accessing electronic data, the data comprising polygonal data representing a surface;   receiving an indication from a user, the indication identifying first and second vertices;   in response to the indication, automatically retopologizing a region of the polygonal data, wherein the automatically retopologized region comprises a plurality of faces and a plurality of edges, wherein automatically retopologizing the region comprises:
 the computer system determining locations for additional vertices to be added to the polygonal data, wherein the additional vertices define a plurality of quadrilateral polygons, wherein the locations are determined based on criteria comprising:
 the topology of polygonal data in the locations is less than a threshold, 
 the locations are within a boundary of the polygonal data, and 
 the locations are outside a previously retopologized region of the polygonal data. 
 
   
     
     
         2 . The method of  claim 1 , wherein automatically retopologizing the region further comprises:
 determining locations for the additional vertices such that one or more of the quadrilateral polygons are substantially square.   
     
     
         3 . The method of  claim 2 , wherein automatically retopologizing the region further comprises:
 determining locations for the additional vertices such that one or more of the quadrilateral polygons have first and second opposing edges which have lengths about equal to the lengths of the substantially square quadrilateral polygons and have third and fourth opposing edges which have lengths which are shorter than the lengths of the substantially square quadrilateral polygons.   
     
     
         4 . The method of  claim 3 , wherein one of the first and second opposing edges forms a portion of a boundary of the retopologized region. 
     
     
         5 . The method of  claim 1 , wherein automatically retopologizing the region further comprises repositioning the additional vertices such that the acuteness and obtuseness of the angles of the quadrilateral polygons is optimized. 
     
     
         6 . The method of  claim 1 , wherein the indication comprises placing an edge dragged from an edge connecting the first and second vertices. 
     
     
         7 . The method of  claim 1 , wherein the indication comprises dragging an edge connecting the first and second vertices greater than the distance between the first and second vertices. 
     
     
         8 . The method of  claim 1 , wherein automatically retopologizing the region further comprises the computer system adding an additional pair of vertices to the polygonal data for each fixed distance an edge connecting the first and second vertices is dragged, wherein each pair of additional vertices partially defines a next quadrilateral polygon. 
     
     
         9 . The method of  claim 8 , wherein the fixed distance is equal to the distance between the first and second vertices. 
     
     
         10 . The method of  claim 8 , wherein the dragging of the edge defines a nonlinear curve, and wherein the each next quadrilateral polygon is placed along the curve. 
     
     
         11 . The method of  claim 1 , wherein the indication comprises dragging an edge connecting the first and second vertices of the polygonal data to a previously retopologized region. 
     
     
         12 . A method of producing an electronic geometric model with a computer system, the method comprising:
 accessing electronic data, the data comprising polygonal data representing a surface;   receiving an indication from a user;   in response to the indication, automatically retopologizing a region of the polygonal data, wherein the automatically retopologized region comprises a plurality of faces and a plurality of edges,   wherein the indication comprises dragging an edge connecting first and second vertices greater than the distance between the first and second vertices.   
     
     
         13 . The method of  claim 12 , wherein automatically retopologizing the region comprises the computer system adding an additional pair of vertices to the polygonal data for each fixed distance the dragged edge is dragged, wherein each pair of additional vertices partially defines a next quadrilateral polygon. 
     
     
         14 . The method of  claim 13 , wherein the fixed distance is equal to the distance between the first and second vertices. 
     
     
         15 . The method of  claim 13 , wherein the dragging of the edge defines a nonlinear curve, and wherein the each next quadrilateral polygon is placed along the curve. 
     
     
         16 . The method of  claim 12 , wherein automatically retopologizing the region comprises:
 the computer system adding additional vertices to the polygonal data until a bounded region is retopologized, wherein the bounded region is bounded by one or more of:
 a region having topology greater than a threshold, 
 a boundary of the polygonal data, and 
 a previously retopologized region. 
   
     
     
         17 . A method of producing an electronic geometric model with a computer system, the method comprising:
 accessing electronic data, the data comprising polygonal data representing a surface;   receiving an indication from a user;   in response to the indication, automatically retopologizing a region of the polygonal data, wherein the automatically retopologized region comprises a plurality of faces and a plurality of edges,   wherein the indication comprises dragging an edge connecting the first and second vertices of the polygonal data to a previously retopologized region.   
     
     
         18 . The method of  claim 16 , wherein automatically retopologizing the region comprises the computer system adding an additional pair of vertices to the polygonal data for each fixed distance the dragged edge is dragged, wherein each pair of additional vertices partially defines a next quadrilateral polygon. 
     
     
         19 . The method of  claim 17 , wherein the fixed distance is equal to the distance between the first and second vertices. 
     
     
         20 . The method of  claim 17 , wherein the dragging of the edge defines a nonlinear curve, and wherein the each next quadrilateral polygon is placed along the curve. 
     
     
         21 . The method of  claim 17 , wherein automatically retopologizing the region comprises:
 the computer system adding additional vertices to the polygonal data until a bounded region is retopologized, wherein the bounded region is bounded by one or more of:
 a region having topology greater than a threshold, 
 a boundary of the polygonal data, and 
 a previously retopologized region.