Patent ID: 7996621

Claim:
A method of managing data in a memory cache, the method comprising: setting a first current step value representing a first dynamic spatial index for the three-dimensional scene at a first point in time, the first dynamic spatial index being stored in a first address range of the memory cache, the memory cache further storing a static spatial index for the three-dimensional scene in a second address range of the memory cache; creating a cache directory entry having a local step value in a cache directory within the memory cache, wherein the cache directory entry corresponds to data within the memory cache, wherein the data represents the first dynamic spatial index, wherein the local step value represents at least one of: (i) the first dynamic spatial index and (ii) a second dynamic spatial index for the three-dimensional scene at a second point in time prior to the first point in time; receiving a request to retrieve data at an address corresponding to the cache directory entry; comparing at least the local step value with the first current step value to determine if at least one of a cache hit or a cache miss occurs; and upon determining that a cache miss occurs, invalidating the second dynamic spatial index without invalidating the static spatial index.