| 摘要 |
A method for generating subdivision surfaces in real-time for use in connection with computer graphics is provided. According to an exemplary embodiment of the method, face information and subdivision data for a subdivided face are generated. The subdivided face is made up of a number of subdivision surfaces. The face information and subdivision data for the subdivided face respectively include vertices and edges, which define the subdivided face. Furthermore, two bitflags are associated with each edge identified in the subdivision data for the subdivided face. One bitflag is used to identify whether the associated edge is being used for a second time and the other bitflag is used to indicate whether the associated edge is used twice. The subdivision data for the subdivided face is then used to generate subdivided and additional edges. Each edge identified by the subdivision data for the subdivided face is defined by a pair of subdivided edges. If an edge is used twice and is being used for the second time, the order of the subdivided edges which make up the edge is reversed. The face information for a subdivision surface is then generated using the face information and subdivision data for the subdivided face, and the subdivision data for the subdivision surface is generated using the subdivided and additional edges. Similarly, the face information and subdivision data for the subdivision surface respectively include vertices and edges, which define the subdivision surface; and two bitflags are associated with each edge identified in the subdivision data for the subdivision surface. After the respective face information and subdivision data for the subdivided face and subdivision surfaces are generated, new vertices are created for each edge which defines the subdivided face. An interior vertex bitflag is used to indicate whether a newly created vertex is an interior vertex. If the new vertex is an interior vertex, then using a standard (3/8, 3/8, 1/8, 1/8) vertex weighting system, the blending weight for an edge-sharing neighbor vertex is halved. All the vertices are then displaced to create a smoother subdivided face. |
