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@@ -71,7 +71,7 @@ scientific and commercial visualization, training through to modeling programs.
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<h3>
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<u>Why use a Scene Graph - Performance, Productivity, Portability and Scalability</u>.</h3>
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<ol><i>Performance</i> - scene graphs provide an excellent framework for
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<ol><b><i>Performance</i></b> - scene graphs provide an excellent framework for
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maximizing graphics performance. A good scene graph employs two key techniques
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- culling of the objects that won't be seen on screen, and state sorting
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of properties such as textures and materials, so that all similar objects
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@@ -83,7 +83,7 @@ with just a few operations! Without state sorting, the the buses and GPU
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will thrash between states, stalling the graphics pipeline and destroying graphics
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througput. As GPU's get faster and faster, the cost of stalling the graphics
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is also going up, so scene graphs are becoming ever more important.
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<p><i>Productivity</i> - scene graphs take away much of the hard work required
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<p><b><i>Productivity</i></b> - scene graphs take away much of the hard work required
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to develop high performance graphics applications. The scene graph manages
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all the graphics for you, reducing what would be thousands of lines of
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OpenGL down to a few simple calls. Furthermore, one of most powerful concepts
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@@ -96,12 +96,12 @@ helping users set up and manage graphics windows to importing of 3d models
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and images. All this together allows the user to achieve a great deal with
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very little coding. A dozen lines of code can be enough to load your data
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and create an interactive viewer!
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<p><i>Portability</i> - scene graphs encapsulate much of the lower level
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<p><b><i>Portability</i></b> - scene graphs encapsulate much of the lower level
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tasks of rendering graphics and reading and writing data, reducing or even
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eradicating the platform specific coding that you require in your own application.
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If the underlying scene graph is portable then moving from platform to
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platform can be as simple as recompiling your source code.
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<p><i>Scalability</i> - along with being able to dynamic manage the complexity
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<p><b><i>Scalability</i></b> - along with being able to dynamic manage the complexity
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of scenes automatically to account for differences in graphics performance
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across a range of machines, scene graphs also make it much easier to manage
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complex hardware configurations, such as clusters of graphics machines,
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@@ -123,7 +123,7 @@ development model to provide a development library that is legacy free
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and well focused on the solving the task. The OpenSceneGraph delivers on
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the four key benefits of scene graph technology outlined above using the
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following features:
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<ol><i>Performance</i> - supports view frustum culling, occlusion culling, small feature culling,
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<ol><b><i>Performance</i></b> - supports view frustum culling, occlusion culling, small feature culling,
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Level Of Detail (LOD) nodes, state sorting, vertex arrays and display
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lists as part of the core scene graph. These together make the OpenSceneGraph
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one of the highest performance scene graph available. User feedback is that
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@@ -134,7 +134,7 @@ of Detail (CLOD) meshes on top the scene graph. These allow the visualization
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of massive terrain databases interactively, examples of this approach can
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be found at Vterrain.org and TerrainEngine.com, both of which integrate
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with the OpenSceneGraph.
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<p><i>Productivity</i> - by combining lessons learned from established
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<p><b><i>Productivity</i></b> - by combining lessons learned from established
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scene graphs like Performer and Open Inventor, with modern software engineering
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boosts like Design Patterns, along with a great deal of feedback early on
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in the development cycle, it has been possible to design a library that is
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@@ -143,7 +143,7 @@ to the OpenSceneGraph and to integrate it with their own applications. With
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a full feature set in the core scene graph, utilities to set up the scene
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graph and viewers and a wide range of loaders it is possible to create
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an application and bring in user data with a very small amount of code.
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<p><i>Portability</i> - The core scene graph has also been designed to
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<p><b><i>Portability</i></b> - The core scene graph has also been designed to
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have minimal dependency on any specific platform, requiring little more than
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Standard C++ and OpenGL. This has allowed the scene graph to be rapidly
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ported to a wide range of platforms - originally developed on IRIX, then
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@@ -154,7 +154,7 @@ In the distribution there is already the osgProducer library, and in the Bazaar
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found at openscenegrph.org/download/ one can find examples of applications
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written on top of Qt, MFC, WxWindows and SDL. Users have also integrated it
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with Motif, and X.
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<p><i>Scalability</i> - the scene graph will not only run on portables all
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<p><b><i>Scalability</i></b> - the scene graph will not only run on portables all
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the way up to Onyx Infinite Reality Monsters, it supports the multiple
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graphics subsystems found on machines like a mulitpipe Onyx. This is
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possible because the core scene graph supports multiple graphics contexts
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@@ -162,10 +162,10 @@ for both OpenGL Display Lists and texture objects, and the cull and draw
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traversals have been designed to cache rendering data locally and use the
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scene graph almost entirely as a read-only operation. This allows multiple
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cull-draw pairs to run on multiple CPU's which are bound to multiple graphics
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subsystems. This has been demonstrated using the OpenSceneGraph in conjunction
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with SGI's OpenGL multipipe SDK. We also have osgMP in development, which
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will be cross platform and will transparently support multiple multipipe systems
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like the Onyx and graphics clusters</ol>
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subsystems. Support for multiple graphic context and multi-threading is all
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available out of the box via osgProducer - all the examples in the distribution
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can run multi-pipe just by use a simple configuation file.</ol>
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All the source to the OSG is published under the GNU Lesser General Public License
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(LGPL) which allows both open source and closed source projects to use,
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modify and distribute it freely as long its usage complies with the LGPL.
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@@ -180,7 +180,7 @@ the contributions of the rest of the community, but this hasn't impacted
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the quality of the source or support which once you get stuck in you grow
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to appreciate.
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<p>The project is currently in beta, which means the main core features are now in
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place, with a 1.0 release in fall 2002. Despite the beta development status,
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place, with a 1.0 release in second half of 2003. Despite the beta development status,
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the project has already earned the reputation the leading open source scene
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graph, and is establishing itself as a viable alternative to the commercial
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scene graphs. Numerous companies, university researchers and graphics enthusiasts
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@@ -211,15 +211,15 @@ instructions for how to get the OpenSceneGraph compiling and installed
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on your system. You may also need to download libraries that parts of the
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OpenSceneGraph depend upon, such as Producer. Check the <a href="dependencies.html">dependencies</a>
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list for further details.
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<p>For full instructions of how to run the demos read the <a href="examples.html">demos</a>
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<p>For full instructions of how to run the examples read the <a href="examples.html">examples</a>
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page.
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<br>
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<hr>
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<h3>
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<u>Learning how to use the OpenSceneGraph</u></h3>
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The OpenSceneGraph distribution comes with a reference guide for each of
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the component libraries - osg, osgDB, osgUtil, osgText, osgParticle and osgProducer, a set
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of demos - the source of which can be found in examples. For questions
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the component libraries - osg, osgDB, osgUtil, osgText, osgSim, osgParticle and osgProducer, a set
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of examples - the source of which can be found in examples. For questions
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or help which can't be easily be answered by the reference guide and demo
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source, one should join the mailing list (details below). There are also
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the beginnings of a <a href="http://www.c2.com/cgi/wiki?OpenSceneGraphFaq">Wiki
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Robert Osfield