Abstract: Data is shared over a network which has a plurality of network connected terminals, each including memory and a processor. The memory includes instruction for managing object duplication, wherein in response to a data requirement of a first of the network terminals, a second of the network terminals duplicates the object at the first terminal. Data is accessed is the using locally executed object instructions at the first terminal. Data consistency is maintained between duplicated objects. said the duplicate objects include a duplicate master and duplicates and, performing a load balancing task or in the case of a network connectivity failure, the respective state thereof may be switched.

Abstract: Data structures within a shared computer-generated environment, are updated. A user terminal has memory a processor, input, network connection and a display. The memory stores data structures and instructions. The instructions configure the processor to supply an output image on a frame-by-frame basis to the output display by rendering the data structures. The data structures are updated in response to input data from another network-connected terminal or in response to delayed locally-generated input data received from the input. The data structures are extrapolated to produce output data if the data structure has not been updated in response to network input or in response to delayed locally-generated input.

Abstract: The present invention provides a computer network configured to define and update data structures within a shared computer-generated environment, wherein a local instantiation 1001 of one of said data structures is known as a duplicate master 805 and updates remote instantiations 1004 of said data structure known as duplicas 804 according to distance-based Position History-Based Dead Reckoning 906. Said updating operation 906 according to distance-based PHBDR minimises the amount of data 1402 transmitted for the purpose thereof and the quality factor 1601 implemented according to an improved embodiment of the present invention dynamically maximises (1501, 1502, 1503) the usage made of the network bandwidth 702 available at any time.

Abstract: Apparatus is provided to share and update data structures within a shared computer-generated environment, including a user terminal having memory means, processing means, input means, network connection means and display means, wherein said memory means stores said data structures and instructions, whereby said instructions configure said processing means to supply an output image on a frame-by-frame basis to said output display means by rendering said data structures; update said data structures in response to input data from another network-connected terminal or in response to delayed locally-generated input data received from said input means; and extrapolate said data structures to produce output data if said data structure has not been updated in response to network input or in response to delayed locally-generated input.

Abstract: A computer network is configured to define and update a shared computer-generated environment. A serving computer divides a computer-generated environment into a plurality of cells. A plurality of user computer terminals have display devices, storage, processing capability and a connection to the network. A first user computer terminal defines an entry in the computer-generated environment in one or in a plurality of adjoining cells. The network connection receives notification data about other users sharing cells occupied by the first user. A list of users are stored that share or have shared cells occupied by the first user. The processing capability generates a message for another user identified in the list and generates a local representation of the environment in response to data received from other users and in response to user movements. In this way, it is possible for a very large number of users to share a common computer-generated environment using available networking and processing capabilities.