Efficient geometric tessellation and displacement

摘要

Methods and computer-storage media are provided for rendering three-dimensional (3D) graphics by tessellating objects using novel structures and algorithms. Rendering utilizing “patches,” configurable functions that include a specified number of control points, allows for computation on a per-patch or per-control-point basis, in addition to traditional per-vertex, per-primitive, and per-pixel methods. This produces a number of advantages over previous tessellation methods, including the reuse of computations across existing vertices and the ability to process at a lower frequency. The operations to compute points are simplified in order to optimize system resources used in the process. Transitions from un-tessellated to tessellated objects are smoother utilizing the present invention, while developers have more flexibility in the level of detail present at different edges of the same patch. Detail within a displacement map also can be increased without negative effects associated with previous systems and methods.

主权项

1. A computer-implemented method of geomorphing a three-dimensional (3D) graphics object, wherein the object is graphically rendered utilizing one or more patches made up of graphics primitives, the method comprising:
defining the one or more patches, wherein each patch is defined by a configurable function and a number of control points; selecting one or more first tessellation factors for tessellation for each patch, wherein the one or more tessellation factors comprise a value associated with tessellation of an edge or with tessellation of an interior, the one or more tessellation factors partition using power-of-two tessellation; and creating a sense of increased detail of the object based on generating data points on a displacement map, a data point when generated is provided in a fixed location for subsequent increases in tessellation; increasing a level-of-detail for the object by modifying one or more of the one or more first tessellation factors, wherein modified values are second tessellation factors that are the first tessellation factors multiplied by a multiple of two; and in response to increasing the level of detail for the object, blending additional data points into the displacement map based on data points generated using the second tessellation factors and wherein the multiplying of the power-of-two tessellation factor results in only uniform segments between the additional data points.