A system and method for displaying different portions of an object in different levels of detail

摘要

A data structure provides a framework for relating the levels of detail (LOD) of an object having multiple LODs. A designer is provided the flexibility to display different portions of an object in multiple LODs. An object is stored in different LODs. Each LOD includes one or more polygons, with each polygon representing a portion of the object. An example tree data structure includes nodes which correspond to portions of the object. All nodes at a particular level together represent an object at a corresponding LOD. A function is provided for each edge of a geometrical entity in each node. The functions are weighted according to several factors/attributes. The functions are evaluated dynamically to determine whether to replace a polygon with polygons at a finer LOD. By a proper choice of the functions in different nodes, different portions of the object may be displayed at different LODs.