Patent ID: 7289131

Claim:
A method of interactively rendering a graphics image comprising: providing an image that includes objects, said objects being 2D projections of one or more 3D objects; displaying a current frame of the image; receiving user input regarding changes to be made to the image; determining from said user input, as to each object in the image, if the object is to be changed and thus displayed differently in a next frame; determining a first bounding region of each changed object, said first bounding region containing the object's position in a previous frame; determining a second bounding region of each changed object, said second bounding region containing the object's position in the next frame; adding the first and second bounding regions to an aggregate region; and rendering the image only within the aggregate region, wherein a front buffer is used to display the current frame, a back buffer is used to store objects as displayed in the previous frame and changes to objects from the current frame for display in the next frame, wherein the roles of front and back buffers are switched after each frame display, and wherein each of the first and second bounding regions and the aggregate region are stored in a separate data structure from the front or the back buffers.