Abstract: Spherical-like textures are useful to simulate reflections and to generate arbitrary views from a point. For addressing simplicity, graphics systems typically require rectangular arrays of texture samples but an infinite variety of functions can be used to map these samples to a sphere-like object. A new metric is presented for measuring how well various maps use a given number of samples to provide the greatest worst-case frequency content of the image everywhere over the sphere. Using this metric and other important local properties, a comparison is presented of maps used previously in computer graphics as well as other mapping techniques borrowed from cartography. Based on these analysis several novel mapping techniques are presented that are fairly simple to implement and significantly more efficient in terms of the amount of processing and data required, and the quality of the resulting images.

Abstract: Spherical-like textures are useful to simulate reflections and to generate arbitrary views from a point. For addressing simplicity, graphics systems typically require rectangular arrays of texture samples but an infinite variety of functions can be used to map these samples to a sphere-like object. A new metric is presented for measuring how well various maps use a given number of samples to provide the greatest worst-case frequency content of the image everywhere over the sphere. Using this metric and other important local properties, a comparison is presented of maps used previously in computer graphics as well as other mapping techniques borrowed from cartography. Based on these analysis several novel mapping techniques are presented that are fairly simple to implement and significantly more efficient in terms of the amount of processing and data required, and the quality of the resulting images.

Abstract: A software object security mechanism addresses system security risks that arise due to interactions between software objects. Conditions are imposed on the accessing of targets by accessing object instances according to attributes of the accessing object and the target object that is being accessed. One security feature is that an owner identifier is incorporated into objects. The owner identifier includes identification of the user, person, or entity (e.g., corporation) who or that creates the object, or identification of a computer system used by the user, person, or entity to create the object definition. The owner identifier provides a basis for distinguishing the creator of an object from the user of that object. Another security feature is a set of access authorizations that allow different access rights to be made available to different object creators. In one implementation the access authorizations are All, Owner, and Exemplar.

Abstract: Updating of local object databases at client computers, dynamic inheritance, and event notification methods cooperate to provide a persistent object oriented multi-user domain capable of supporting multimedia presentation features for large numbers of users over conventional networks like the Internet. This includes distributing the objects of such a domain between a server and multiple clients and providing the objects with multimedia presentation features. Such a domain includes the persistence of conventional text-based MUDs and MOOs while also giving users the ability to vary or control a wide range of object attributes and properties. As a result, multimedia (e.g., graphical) presentation capabilities are combined with persistence and variability features of text-based MUDs and MOOs to provide a rich, dynamic, multimedia virtual world environment suitable for standard networks.

Abstract: A dynamic or latebound event mechanism provides event mechanism operation according to associational relationships among objects. In addition, objects may be responsive to event notification methods that are not initially within the original object definition, thereby allowing the event notification methods to be inherited by objects dynamically during run-time. One implementation utilizes the associations Self, Contents, and Peer for objects representing entities in a virtual world environment. Event notifications methods are promulgated among the objects corresponding to the entities in a sequence based upon the associational relationships between the entities.