System for Designing Graphical Multi-Participant Environments

This invention relates to a system for designing a graphical environment, such as a computerized virtual reality location. More particularly, it relates to a system for designing a graphical environment with multiple creators and participants.

Virtual reality systems present images to a user representing scenes at a location, either real or imaginary. In such a system, the user may move around the location or take actions which alter the scene. For example, in an outdoor location, the user may move down a street or path passing buildings, trees, and other objects. The scene changes as the user moves. The user may turn to face different directions which also causes the scene to change. The user may also move or pick up objects. One of the difficulties for a creator of a virtual reality system is the need to create a large number of scenes with different characteristics. Typically, this is done by specifying the objects (such as buildings, trees, vehicles, etc.) at each location.

Often virtual reality systems have multiple participants. The participants move around in the location and interact with each other. Typically, the participants have different goals, objectives, and expectations about the virtual reality location.

The design of the location must account for these differences. In order to provide greater diversity, the system creator may allow the participants to assist in generating portions of the location, with corresponding characteristics. Creation by multiple participants raises additional problems of integration and joint operation.

Lucasfilm Games created a system called "Habitat" which is a multi-user, on-line simulated world. The operations and problems with this world are discussed in C. Morningstar and F. R. Farmer, "The Lessons of Lucasfilms', Habitat" Cyberspace: First Steps (ed. M. Benedikt, 1991). In this system, online participants see views of a world with characters representing themselves and other participants acting within the world. One of the difficulties for Habitat was the creation of a world capable of supporting a population of thousands or tens of thousands of participants. The creators of Habitat tried to centrally plan and generate the entire world. With large numbers of participants, the world had to be large and to include things to do which would be of interest to the various participants. This required the design of many buildings, road networks, objects, and areas. Furthermore, in order to generate interest, the designs had to be diverse. Respective designs and architectures are uninteresting in the real world and in virtual reality. This proved to be extremely difficult for the central planner. Thus, a need exists for a system which allows the creation of a large scale virtual reality environment with diversity.

Urban planners have used systems which describe locations in general terms. The Image of the City (1960) by Kevin Lynch describes five elements that people use to organize a mental image of a city or region. "Districts" are broad regions, such as neighborhoods, which have some common identifying character. "Paths" are channels, such as roads or walkways, along which an observer can move. "Edges" are boundaries between districts. "Nodes" are specific objects to and from which an observer may travel. Finally, "landmarks" are points used for general orientation, locally or globally. While these constructs are used for understanding, describing, and designing real-world cities or other locations, they have not been used for designing places in virtual reality environment.

Therefore, a need exists for a system to allow generation of a virtual reality location by multiple participants. A need also exists for a system which provides structure to the virtual reality environment. A need also exists for a system which allows for diversity in the creation of the environment.

The present invention overcomes the deficiencies of the prior art by providing a system for creation of a graphical environment, such as a virtual reality location, through application of urban planning constructs. The environment is created by defining districts, paths, edges, nodes, and landmarks within the environment. The districts are further defined by the characteristics which represent that district, such as the types and styles of objects within the district. Scenes provided to a participant moving within the environment are generated, based upon the characteristics of the districts within the environment. In particular, the participant moves along defined walkways, which may or may not include specific designated paths, through the environment. At positions along the walkway, scenes are developed based upon stored images representing characteristics within each district or representing the different nodes and landmarks.

FIG. 1 is a block diagram computer system which can be used in the system of the present invention.

FIG. 2 illustrates a graphical depiction of an environment created using the system of the present invention.

FIG. 3 represents a street level scene of the present invention.

FIG. 4 is a block diagram representing the steps in operation of the present invention.

The present invention may be implemented using a computer system, such as the system illustrated in block diagram form in FIG. 1, for creating, storing, and changing the graphical environment, and generating scenes of the environment. A CPU 10 processes instructions stored in a memory 20 in order to perform the functions of the system. Users or participants each have a terminal 40, 50 for connecting to the CPU 10. Each user terminal may include a separate computer, which performs part of the processing. At a minimum, each terminal includes an input device, such as keyboard 42, 52, and an output device, such as display 41, 51, for interacting with the system. Of course, other types of input and output devices can be used. A separate input port 30 may be connected to the CPU to input data used by the system. The inputted data may include designs of the environment, or specific elements to be used in developing a scene within the environment. The memory 20, which can be one or more of various kinds, including RAM, ROM, CD-ROM, and combinations, must be of sufficient size to store both the instructions for operating the CPU and the data for generating the environment and scenes from the environment. Of course, multiple, different memories can be used for storing data, rather than a single memory as illustrated in FIG. 1.

FIG. 2 illustrates the design of an environment using the system of the present invention. As illustrated, the environment is designed using the five elements identified by Lynch in describing an image of a city. The participants or creators add to the environment by selecting and placing these elements at different locations within the environment. When modifying the environment, a view of the environment, as illustrated in FIG. 2, is displayed on the user's display 41. Using the keyboard 42, or other input device, the user selects specific elements and places them within the environment on the display. The user may also enter characteristics of the element. In particular, the actual objects which are the nodes and landmarks need to be identified. As illustrated in FIG. 2, the environment 100 includes districts 111, 112, 113. Each district has certain boundaries and characteristics which are used for generating the scenes within the environment. The edges or boundaries 121, 122 divide districts and represent locations for changes between characteristics in the different areas. Of course, an edge does not need to be specifically identified, since the locations of districts identify the boundaries between them. Nodes 131, 132 represent different foci, such as specific buildings or other locations within the environment. Landmarks 141, 142 also represent specific elements within the environment, such as mountains or recognizable buildings. The paths 151, 152 are illustrated as passing throughout the districts within the environment. Finally, a walkway 160 is defined within the environment which represents the progression of one of the participants through the environment. A walkway is not one of the urban planning constructs. Instead, it is used to generate the scenes in the virtual reality environment.

Once the environment is created and a walkway for a participant has been laid out, the system generates a set of scenes representing movement along the walkway through the environment. An example of the format for a scene is illustrated in FIG. 3. While FIG. 2 represents a conceptual "birdseye" view of the environment, the scenes represent a ground level view at specific locations along the walkway. In essence, the scenes represent a transformation from a conceptual city view to a specific human view of the structural elements which are part of the environment. As illustrated in FIG. 3, the scenes may be a perspective view of composited objects. These objects can include the ground 210, the sky 220, facades of buildings 231, 232 and specific freestanding objects, such as a tree 241 or parking meter 242. Of course, with more sophisticated rendering systems, the scene may be developed as actual 3D images of specific objects, positioned along the walkway.

Diversity in the environment is achieved by selecting specific characteristics representing each of the districts, in addition to the specific nodes and landmarks created within the environment. The characteristics of a district may define the types of structures which exist along a walkway. For example, a district may have certain types of buildings (wood-clapboard triple deckers), certain types of paths, (asphalt roadways with brick lined sidewalks), and specific objects (trees, fire hydrants, parking meters) along the route. As these scenes develop representing movement along the walkway, the objects within the scene are based upon the characteristics of the district to which the scene corresponds. As the participant moves along the walkway into another district, the flavor of the scenes change. The objects in the scenes are revised to reflect the new characteristics of the new district. While the districts have been discussed as locations within a city, the environment is not limited to a city. The districts may also represent natural areas having common characteristics such as parks, wilderness areas, mountains, bodies of water, or other types of areas which might be encountered by a specific observer.

FIG. 4 illustrates, in a block diagram format, the functions performed by the present invention. The first three steps 310, 320, 330 relate to generation of the conceptual view of the environment. At step 310, a user inputs specific elements and their location within the environment. In addition to defining the element and their locations, the user may need to include data defining the view of the element.

Once the elements have been selected and located, the system generates a conceptual view of the city (step 320). This view is represented in FIG. 2.

In order for a user to operate within the environment, a walkway must be determined through the environment. This walkway may be preplanned, such as illustrated by walkway 160 in FIG. 2, or may be revised in real-time as the participant interacts with the environment. Certain characteristics of the different districts are pre-defined and stored in an adjunct database. The district characteristics are identified in step 330. As discussed above, the characteristics for district identify the types of objects and the looks of the objects which are encountered within that district. Finally, at step 350, the system generates scenes encountered along the walkway. The scenes are generated based upon the characteristics of the district in which each scene is located within the environment. As illustrated in FIG. 4, the system of the present invention does not require a straight progression through each of the steps 310-350. Rather, from any step the user can proceed through any other step in order to change the environment or revise the walkway through the environment.

Having now described a few embodiments of the invention, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention as defined by the appended claims.