SAN JOSE, CA -- NOVEMBER 7, 1995 -- MultiGen Inc., the leader in realtime 3D authoring software, today announced that it has put its popular OpenFlight� scene description database specification into the public domain. The company also announced that it is working with M�K Technologies of Cambridge, MA, to supply extensions to the OpenFlight database standard, providing an open and available Internet framework for delivering multiuser realtime 3D applications.

MultiGen also announced twelve new companies joining the movement to OpenFlight, including: Animetix, ELSA, Evans and Sutherland, Intergraph, Lightscape, LightSpeed, Lockheed Martin, NorControl, Oktal, OmniComp and Syndesis.

MultiGen and M�K will release an OpenFlight API this February, which includes structures for linking to M�K's Distributed Interactive Simulation (DIS) network protocols. This will give the Internet community an open, multiuser realtime 3D environment previously available only to high-end visual simulation users. MultiGen will extend the API by Q3 '96 with new multimedia entities, plus support for Sun's Java scripting language.

These developments represent a very significant step in accelerating the move to users running interactive, realtime 3D applications securely over the Internet. To date, no viable standard has emerged for multiuser realtime 3D applications on the World Wide Web.

OpenFlight with DIS represents the most efficient and scalable data structure that is available and proven for video games, location-based entertainment, CAD visualization and training simulation. OpenFlight enables developers to deliver highly realistic synthetic 3D environments that are user-controlled and run over networks, in full detail, in realtime.

MultiGen� OpenFlight� Question and Answers

Q. Where did OpenFlight originate, and how wide is its use?
A. OpenFlight has been developed over the last ten years at MultiGen Inc. There are thousands of OpenFlight databases in existence today, and thousands more are being produced each year. OpenFlight has become a defacto standard in a wide range of interactive 3D industries including flight and driving simulation, entertainment and CAD visualization. Over 750 professionals are creating OpenFlight databases using MultiGen's 3D authoring software products.

Q. What makes OpenFlight unique in its approach to describing 3D scenes?
A. OpenFlight is uniquely described by the following characteristics:

Efficient - Since 3D entities are described as polygonal models and 2D textures, OpenFlight scenes can be drawn quickly with minimum load on processors and delivered via networks of limited bandwidth.

Scalable - OpenFlight is used to describe of range of 3D scenes, from the simplest rooms to real-world terrain with photo-realistic texture maps that extend for hundreds of thousands of miles.

Hierarchical - OpenFlight is a hierarchical database, which builds power into the editing and retrieval process, allowing for level of detail (LOD) and culling control.

User-Driven - OpenFlight databases are under user, not author command. This differentiates OpenFlight from every Animation 3D database structure, where the author pre-determines the visual interaction in an a priori way.

Multi-Platform - OpenFlight databases are routinely used on a complete range of rendering platforms including high end image generators, SGI workstations, PC's, Macs and realtime game consoles from Nintendo, Sony and Sega.

Q. Besides hierarchy, geometry, and texture, what data is described in OpenFlight?
A. OpenFlight includes dozens of attributes that go beyond visual scene descriptions. These include sound emitters for audio effects, light sources, BSP trees, degrees of freedom (descriptions of how objects can move and rotate), and linkages (a way to control scene elements from internal and external data values). Equally important, OpenFlight can be extended to describe any application-specific data by utilizing variable length text fields associated with any node of the hierarchy, or by defining private, application specific, hierarchy nodes.

Q. Why is putting OpenFlight in the public domain important?
A. It is important because the area of interactive 3D scene description is suddenly a very hot topic, and we feel like we have something significant to contribute. OpenFlight is both rich and mature, and is already widely used and accepted. By putting it in the public domain, we are offering the emerging low cost 3D industry a format that contains all the necessary elements and attributes for sophisticated 3D realtime graphics. At the very least, because of its completeness, OpenFlight has become an important interchange standard in realtime 3D scene description, just as PostScript has for 2D page description.

Q. What does it mean to add MAK's DIS protocols to OpenFlight structures?
A. MAK's environment is based on the ARPA-pioneered Distributed Interactive Simulation (DIS) standard. Throughout the VisSim community, OpenFlight and DIS are used together to provide realtime methods for users to see, add and modify entities over a local or wide area network. Information messages includes model placement and position, dynamics and collision detection. Network gameplay with over 5,000 entities at over 20 sites has run successfully with this combination.

Q. How does Scene Description Database differ from a Scene Description Language?
A. Both are ways to describe 3D worlds. Typically, a language is text, which is parsed, then compiled or interpreted before it can be used to draw 3D scenes. A complex language has all the power of a programming language such as subroutines and pseudo-variables. Languages also have the advantage of a text editor, but they are subject to problems such as syntax errors and bugs. The more complex the language, the more these problems occur. As a practical matter, complex 3D scenes must be created with a tool rather than manually, even if the scene description language is text based. There can still be problems, however, in verifying that the output of such tools is legal and correct according to the specification of the language syntax. In general, a database provides much more power than a language when it comes to accessing the data. A database is a binary or ASCII file that is accessed via an API. The API has several advantages over a language, among them that no parsing is necessary, data can be randomly accessed by search criteria (e.g. give me all the polygons in this bounded space), and files that are created via the API are guaranteed to be completely legal and syntactically correct.

Q. How does OpenFlight differ from VRML?
A. VRML is a text based language based on SGI Inventor, while OpenFlight is a binary database (see the answer to the previous question). The VRML committee has done a good job designing and publicizing a language to facilitate interactive 3D on the World Wide Web, and it is clear from the response there is overwhelming requirement for an open and secure way to describe 3D worlds on the Internet.

OpenFlight is not based on VRML or Inventor, but rather is a separate, more advanced specification with thousands of high quality realtime 3D databases, developed using MultiGen tools, that can be reused for new applications. OpenFlight's strengths are in scene description for seamlessly describing small to large scale realtime applications. Most of the scene description functionality of VRML can be derived from a subset of OpenFlight. To that end, MultiGen tools read and write VRML files today.

VRML is designed to handle relatively small areas while OpenFlight can easily handle geographical areas that are hundreds or thousands of miles on a side using one of several available coordinate projections. OpenFlight handles many other functions such as morphing between level of detail, plus linkages, behaviors and built-in attributes facilitating scene management that do not exist in VRML.

Q. What are the differences between how the VRML specification is updated and maintained and how OpenFlight is maintained?
A. VRML was designed by a committee with members selected based on either their background or the organization that they represent. Mark Pesce has done a great job of pulling together and mediating between a diverse group of individuals who do not always have the same objectives.

A potential problem seems to be that no organization has dedicated resources, or has the momentum, to take VRML forward. Instead, the process is dependent on every member of the committee doing his part on his own time to move the standard forward. OpenFlight is maintained by MultiGen, Inc., and because it is sponsored by a single organization, updates are guaranteed to occur regularly and support is available. Several engineers are dedicated to the task, and MultiGen already has the systems in place to regularly update the standard. Obviously, the advantage this gives MultiGen is one of editorial control; the costs to MultiGen include handling the API and documentation updates, Web page support, and distribution.

Q. Does this mean that MultiGen believes OpenFlight should replace VRML?
A. That is not our intent, but we do believe that there are some important constructs that OpenFlight implements that should be made part of VRML, and this will take some time. It will be up to the industry and the VRML committee to decide if there is a practical way to merge our ideas with theirs and get the best of both worlds. In the meantime, we are making available the techniques we have developed from hundreds of R&D person years in authoring and delivery of realtime 3D databases. MultiGen leaders have met recently with Mark Pesce to discuss collaboration. We offered and are ready to serve on the VRML committee as he sees best.

Q. How does OpenFlight differ from VRML+?
A. The definition of VRML+ (Worlds, Inc.) is unclear. World's before-tried' ploy has been met with negative industry and VRML community response. On its own Web Site, Worlds describes its WorldsWare(tm) software and WorldServer(tm) host server as "proprietary." This is understandable since Worlds' business model is to use their (again from their Web Site) "talented development organization to produce custom, networked, 3D multi-user environments for companies and their customers." MultiGen welcomes Worlds and others to use MultiGen's off-the shelf 3D authoring tools and OpenFlight database standard for custom development.

Q. How does OpenFlight differ from Inventor?
A. OpenFlight differs in two important ways. First, it has numerous constructs that are not found in current Inventor specification. These include Binary Separating Plane, Degree of Freedom and Linkage nodes. Inventor also implements Level of Detail based only on screen area, not on screen area or distance as with OpenFlight. Second, OpenFlight databases are created by a powerful set of 3D authoring tools from MultiGen that have been available for ten years. These tools, in turn, have enabled the thousands of real-world realtime databases developed, including SGI's own show-stopper called "Performer Town." There are no commercially viable 3D authoring tools available today that fully support the Inventor format.

Q. Where are you going in the future with OpenFlight?
A. In the past, MultiGen has provided the data structures, database source code, and a format description document to extend OpenFlight. This is all changing. In February, we will release an API that will make accessing an OpenFlight database much simpler and will add a significant amount of power to the process. Some of that power includes adding multi-user network database structures that support the MAK DIS protocols. In addition, we are continually refining and enriching OpenFlight. Major components planned by Q396 include support of 3D animation and video, plus attaching scripts (via languages like Java) to 3D models.

Q. Who will be the likely adopters of OpenFlight in the future?
A. MultiGen is moving quickly in establishing the most proven and innovative software framework
for realtime 3D applications. As realtime 3D becomes better known and more accessible in areas outside of visual simulation, (eg. video games, virtual sets, CAD visualization, multimedia titles, educational research), most authoring and delivery environments serving these markets will likely come to MultiGen for aspects of our solution. The computing leaders in these markets include Adobe, Autodesk, Intel, Macromedia, Microsoft, Netscape, SGI and Sun.

Major Users Support OpenFlight

• Content Developers - Rare, Viewpoint, Xatrix, Zipper, Zombie;
• Institutions - Beijing Institute, Samsung Institute of Technology,University of California at Los Angeles, University of Central Florida, University of Iowa, University of Missouri,
• University of North Carolina;
• Software Vendors - ABACO, Animetix, Clarus, Division, Gemini, Lightscape, LightSpeed, MAK,
• Paradigm, Sense8, Syndesis, Virtus;
• Systems Vendors - 3DFx, ELSA, Intergraph, Nintendo, OmniComp, Silicon Graphics;
• System Integrators - CAE, Dharma Systems, Evans and Sutherland, KCE International, Lockheed
• Martin, Marconi, MediaLab, NASA, NorControl, Oktal, Thomson.

The fast-growing acceptance of OpenFlight will lead to a new generation of high-powered 3D games. "Tools like MultiGen and MAK's VR-Link are critical to the development of the networked game titles of the future," said Mark Long co-founder of game developer Zombie Studios. "As games become larger and more complex, Zombie will need such tools to develop the massively networked titles we want to create."

"MultiGen is the only proven realtime 3D vendor with an industry open and neutral position," said John Latta, president of industry analyst firm 4th Wave in Alexandria, VA. "As game development, CAD visualization and the emerging Web-based markets add realtime 3D content and applications, this powerful and extensible 3D database framework will become the de facto standard in virtually every authoring and playback environment developed and sold."

>Future OpenFlight Developments

• More Multimedia - New 3D animation and video frameworks will be added to complement the 3D graphics and 3D audio entities currently supported.
• Scripted Objects - Via languages like Java, OpenFlight objects will be able to attach embedded scripts to describe behaviors and provide security.

OpenFlight: The Visual Simulation Standard

"OpenFlight is to 3D scenes what PostScript is to 2D pages," said Dennis Yeo, chairman and founder of MultiGen. "OpenFlight is more than a set of file formats to describe the visual and auditory elements of a rich realtime 3D scene. It also describes the structure and linkages that define what, how, when and if objects should be rendered for realtime, providing intelligent trade-offs for all performance levels of APIs and engines, from simulators, workstations and PCs, to game consoles, interactive TVs and the World Wide Web. At the urging of our customers and partners, and with a database so powerful, we felt it was time to put this work into the public domain."

"OpenFlight has naturally evolved to be the de facto 3D database standard in the visual simulation market, without a runner-up in sight," said Warren Katz, co-founder and COO of M�K Technologies. "In conjunction with new protocol features in our VR-Link DIS networking toolkit, we can now directly map networked entity behaviors to components of OpenFlight models, as well as exchange new visual components between networked entities--both transparently and in realtime."

OpenFlight Availability

MultiGen is releasing the current version of the OpenFlight specification this month on both the new MultiGen TakeFlight and Silicon Graphics WebForce sites on the World Wide Web. The specification is also available on the SGI Performer 2.0 CD-ROM that is distributed to all SGI Onyx® system users.

A more detailed Q&A on the OpenFlight Scene Description Database is available by contacting MultiGen or Schwartz Communications, Inc.

M�K Technologies Inc., founded in 1990, is the leading supplier of networking software for realtime simulations and virtual reality applications. Its core product, VR-Link®, implements the Department of Defense's Distributed Interactive Simulation (DIS) network protocol and is being used by leading simulation companies and government organizations worldwide. Dial-a-Tank®, M�K's vehicle simulation toolkit, enables users to rapidly create low-cost DIS simulators for military, civilian and entertainment applications. M�K Technologies is based in Cambridge, MA.

Artwork by Viewpoint Datalabs