Editing OpenSceneGraph

{{Infobox software
| name = OpenSceneGraph
| logo = Osglogo2.0.png
| genre = [[3D graphics]]
| latest release version = 3.6.5
| latest release date    = {{Start date and age|2020|01|31}}<ref>{{Cite web|url=https://www.openscenegraph.com/index.php/download-section/stable-releases|title=Stable releases|website=www.openscenegraph.com}}</ref>
| latest preview version = 
| latest preview date    = 
| operating_system = [[Cross-platform]]
| programming language = [[C++]]
| license = [http://www.openscenegraph.org/projects/osg/wiki/Legal OpenSceneGraph Public License] ([[LGPL]] based)
| website = {{URL|http://www.openscenegraph.org/}}<br />{{URL|http://www.openscenegraph.com/}}
}}{{Primary sources|date=March 2024}}
'''OpenSceneGraph''' is an [[open-source software|open-source]] 3D graphics [[application programming interface]] (library or framework),<ref name=springer>{{cite book|title=Headway in Spatial Data Handling:13th International Symposium on Spatial Data Handling|author=Anne Ruas |author2=Christopher Gold |publisher=Springer|year=2008|page=370|isbn=978-3-540-68566-1|url=https://books.google.com/books?id=wc5gMNG3dIcC&q=OpenSceneGraph&pg=PA370}}</ref> used by application developers in fields such as [[visual simulation]], [[computer game]]s, [[virtual reality]], scientific [[Scientific visualization|visualization]] and [[computer model|modeling]].

The toolkit is written in standard [[C++]] using [[OpenGL]],<ref name=springer/> and runs on a variety of [[operating system]]s including [[Microsoft Windows]], [[macOS]], [[Linux]], [[IRIX]], [[Solaris (operating system)|Solaris]] and [[FreeBSD]]. Since version 3.0.0, OpenSceneGraph also supports application development for mobile platforms, namely [[iOS]] and [[Android (operating system)|Android]].

As of 2021, the project is being succeeded by VulkanSceneGraph project, a Vulkan-based library.<ref>{{Cite web |title=VulkanSceneGraph Project |url=https://openscenegraph.github.io/OpenSceneGraphDotComBackup/OpenSceneGraph/www.openscenegraph.com/index.php/8-news/232-vulkan-vkscenegraph-project.html |access-date=2021-07-05 |website=openscenegraph.github.io}}</ref> OpenSceneGraph is in  maintenance phase since 2019.

== History ==
The OpenSceneGraph project was initiated by Don Burns in 1998. Robert Osfield joined the project during 1999, working on porting finished components for Microsoft Windows. The project went open source in September 1999 and the official [http://www.openscenegraph.org project website] was created. Towards the end of the year Osfield took over the project and began extensive refactoring of the existing codebase, putting emphasis on modernisation, embracing modern C++ standards and [[Design pattern (computer science)|design patterns]].

In April 2001, taking into account growing community of users and interest of public, Robert Osfield created OpenSceneGraph Professional Services, providing commercial support, consulting and training services. This marks full professionalization of the project.

The first official stable version of OpenSceneGraph was version 1.0, released in 2005. An extended version 2.0 followed in 2007, adding support for multi-core and multi-gpu systems, several important NodeKits and usage of unified multiplatform build system [[CMake]]. Books and user handbooks were introduced.<ref name="quickstart">Martz, P.: OpenSceneGraph Quick Start Guide. Louisville, USA,  2007.</ref>

The project has been quickly growing and becoming more popular ever since. There are more than 530 contributors signed under current stable version, and the official mailing list contains thousands of names.<ref name="History">{{Cite web |title=Support/History - osg |url=http://www.openscenegraph.org/projects/osg/wiki/Support/History |archive-url=https://web.archive.org/web/20150526014955/http://trac.openscenegraph.org/projects/osg/wiki/Support/History |archive-date=26 May 2015 |website=openscenegraph.org}}</ref>{{Needs update inline|date=March 2024}}

In 2019, the project was moved to a maintenance phase, the main development effort being routed to its successor project VulkanSceneGraph.<ref name="VulkanSceneGraph">{{Cite web|url=https://www.openscenegraph.com/index.php/8-news/232-vulkan-vkscenegraph-project|title=VulkanSceneGraph Project|website=www.openscenegraph.com}}</ref>

== Features ==
[[File:Architecture of OpenSceneGraph.jpg|thumb|400px|Overview of the openscenegraph architecture.]]

Features in version 1.0:<ref>{{Cite web |title=OSG News |url=http://www.openscenegraph.org/svn/osg/OpenSceneGraph/tags/OpenSceneGraph-2.9.6/NEWS.txt |archive-url=https://web.archive.org/web/20110609185828/http://www.openscenegraph.org/svn/osg/OpenSceneGraph/tags/OpenSceneGraph-2.9.6/NEWS.txt |archive-date=2011-06-09 |access-date=2010-02-20 |website=openscenegraph.org}}</ref>
* A feature-rich and widely adopted [[scene graph]] implementation
* Support for performance increasing features
*# [[View frustum]], small feature and [[occlusion culling]]
*# [[Level of detail (computer graphics)|Level of detail]]
*# State sorting and lazy state updating
*# [[OpenGL]] fast paths and latest extensions
*# Multi-threading and database optimization
* Support for OpenGL, from 1.1 through 2.0 including the latest extensions
* Tightly coupled support for OpenGL Shading Language, developed in conjunction with 3Dlabs
* Support for a wide range of 2D image and 3D database formats, with loaders available for formats such as [[OpenFlight]], [[TerraPage]], [[Wavefront .obj file|OBJ]], [[.3ds|3DS]], [[JPEG]], [[Portable Network Graphics|PNG]] and [[GeoTIFF]]
* [[particle system|Particle effects]]
* Support for anti-aliased [[TrueType]] text
* Seamless support for [[framebuffer]] objects, [[pixel buffer|pbuffers]] and frame buffer render-to-texture effects
* Multi-threaded database paging support, which can be used in conjunction with all 3D database and image loaders
* Large scale, whole earth geospatial terrain paged database generation
* Introspection support for core libraries allowing external applications to query, get, set and operate on all classes in the scene graph, via a generic interface
* Multi-threaded and configurable support for multiple CPU/multiple GPU machines

Features in version 2.8.3<ref>{{cite web | url=http://www.openscenegraph.org/projects/osg/wiki/News/Press/OSG2.8.3 | title=OpenSceneGraph Adds New Features to 3D Graphics Applications | date=April 5, 2010 | archive-url=https://web.archive.org/web/20100415145935/http://www.openscenegraph.org/projects/osg/wiki/News/Press/OSG2.8.3 | archive-date=April 15, 2010}}</ref>
*[[Mac OS X 10.6]] (Snow Leopard) support
*ImageIO support on [[macOS|Mac OS X]]
*3DS file format export and file conversion
*Integrated Autodesk FBX technology
*Integrated FFmpeg support for displaying video file content in 3D applications.
*PLY file format support

Features in version 2.8.4:<ref>http://www.openscenegraph.org/svn/osg/OpenSceneGraph/tags/OpenSceneGraph-2.8.4/NEWS.txt {{Dead link|date=February 2022|fix-attempted=yes}}</ref>
*VS2010 build support

Features in version 3.0.0:<ref>http://www.openscenegraph.org/svn/osg/OpenSceneGraph/tags/OpenSceneGraph-3.0.0/NEWS.txt {{Dead link|date=February 2022|fix-attempted=yes}}</ref>
* OpenGL ES 1.1, and OpenGL ES 2.0 support
* OpenGL 3.x and 4.x support along with associated OpenGL extensions
* Support for Android on tablets and phones
* Support for IOS on tablets and phones (end users applications have already been accepted on the App Store)
* Introduction of Present3D application for immersive 3D presentations
* New extensible serializers that provide new .osgb binary, .osgt ascii and .osgx xml file native formats
* New generalized serializable metadata architecture
* New osgQt library that makes it straight forward to integrate !OpenSceneGraph with Qt, including web browsing via QWebKit.
* New FBX plugin based on the Autodesk FBX DSK that enables reading of the .fbx 3D authoring and interchange format
* New directshow plugin for handling movies under Windows
* New pov plugin for exporting a scene to POV-Ray format, enabling use of POV-Ray to do photo-realistic ray tracing
* New ply plugin for reading ply files
* Revamped 3ds plugin for reading and writing of .3ds files
* Revamped dxf plugin for reading and writing of .dxf files
* Support for Cocoa and 64bit OSX build

==Stable version release history==
{| class="wikitable"
!Version
!Release Date
|-
|3.0
|5 February 2013<ref>{{Cite web|url=http://www.openscenegraph.org/index.php/community/press-releases/104-openscenegraph-3-0-release|title=OpenSceneGraph 3.0 release|last=Torres|first=Jordi|website=www.openscenegraph.org|language=en-gb|access-date=2017-09-23}}</ref>
|-
|3.2
|24 July 2013<ref>{{Cite web |title=OpenSceneGraph 3.2 release |url=https://openscenegraph.github.io/OpenSceneGraphDotComBackup/OpenSceneGraph/www.openscenegraph.com/index.php/community/press-releases/143-openscenegraph-3-2-release.html |access-date=2017-09-23 |website=openscenegraph.github.io |language=en-gb}}</ref>
|-
|3.4
|20 July 2015<ref>{{Cite web |title=OpenSceneGraph-3.4 release |url=https://openscenegraph.github.io/OpenSceneGraphDotComBackup/OpenSceneGraph/www.openscenegraph.com/index.php/community/press-releases/191-openscenegraph-3-4-release.html |access-date=2017-09-23 |website=openscenegraph.org |language=en-gb}}</ref>
|-
|3.4.1
|28 August 2017<ref>{{Cite web |title=OpenSceneGraph-3.4.1 release |url=https://openscenegraph.github.io/OpenSceneGraphDotComBackup/OpenSceneGraph/www.openscenegraph.com/index.php/community/press-releases/220-openscenegraph-3-4-1-release.html |access-date=2017-09-23 |website=openscenegraph.org |language=en-gb}}</ref>
|-
|3.6
|7 April 2018<ref>{{Cite web |date=7 April 2018 |title=OpenSceneGraph-3.6 release |url=https://openscenegraph.github.io/OpenSceneGraphDotComBackup/OpenSceneGraph/www.openscenegraph.com/index.php/community/press-releases/223-openscenegraph-3-6-0-release.html |access-date=2018-08-14 |website=openscenegraph.org |language=en-gb}}</ref>
|-
|3.6.1
|28 May 2018
|-
|3.6.2
|29 June 2018
|-
|3.6.3
|14 September 2018
|-
|3.6.4
|26 July 2019
|-
|3.6.5
|31 January 2020
|}

== Architecture ==
Library architecture can be separated into three main subsets — the core OpenSceneGraph library, osgViewer and a set of NodeKits.

=== Core ===
The base of OpenSceneGraph library can be further divided into four main modules.

====osg====
The core of OpenSceneGraph provides [[Class (object-oriented programming)|classes]] and methods for construction and manipulation of the [[scene graph]]. It contains classes representing various types of [[Node (graph theory)|nodes]], scene geometry, [[OpenGL]] state abstraction, [[Transformation (geometry)|geometric transformations]], as well as mathematical classes for 2D and 3D [[Vector (geometric)|vector]] and [[matrix operation]]s. Advanced [[memory management]] is also included.

====OpenThreads====
The OpenSceneGraph project contains a threading library, ''OpenThreads'', which is a lightweight cross-platform [[Thread (computer science)|thread]] [[computer model|model]]. It is intended to provide a minimal and complete Object-Oriented (OO) thread interface for [[C++]] programmers. It is loosely modeled on the [[Java (programming language)|Java]] thread API, and the [[pthreads|POSIX Threads standards]].

The [[architecture]] of OpenThreads is designed around "swappable" thread models which are defined at [[compile-time]] in a [[Library (computer science)#Dynamic linking|shared object library]].  It is of importance to note that while a [[factory method pattern|factory pattern design]] could have been used to achieve the goal of generic [[Interface (computer science)|interface]], it would have required the programmer to allocate each of the 4 fundamental types (Thread, Mutex, Barrier, & Condition) on the [[heap (programming)|heap]].  Due to the cost associated with heap allocation of the underlying concrete implementations of these constructs on some platforms, such allocation was deemed unacceptable at the time this library was originally written, and thus the factory pattern was not used.

Instead, a somewhat abstruse - but effective - technique was chosen to provide the necessary [[data hiding|data/implementation hiding]].  This technique uses private [[void pointer]]s to encapsulate object private data.  The void pointers actually point at concrete data structures, but give a uniform interface to the dso.

The design goal of OpenThreads is to construct optimized implementations using platform optimized multi-processing constructs such as the [[Fork (system call)#Rfork|sproc]] methods used on IRIX, and Windows threads.

====osgUtil====
osgUtil contains [[Rendering (computer graphics)|rendering]] [[Front and back ends|backend]] functionality and utilities taking care of scene [[graph traversal]], rendering [[Optimisation (computer science)|optimisation]] and transforming the scene into a stream of [[OpenGL]] API calls. It also provides means of basic interaction with scene, such as object picking.

====osgDB====
This library is tasked with loading 3D model files. It supports many 2D/3D data [[File format|formats]] manipulators. More than 50 different formats are supported - most common are 3D data formats, such as [[Collada|COLLADA]] (.dae), [[LightWave]] (.lwo), [[Wavefront .obj file|Wavefront]] (.obj), [[OpenFlight]] (.flt), [[3D Studio Max]] (.3ds), [[DirectX]] (.x) and many others. OpenSceneGraph also provides its own native [[ASCII]] .osg format. There are exporters into .osg format available for [[Blender (software)|Blender]], [[Maya (software)|Maya]] and 3D Studio MAX.

Supported picture formats include .rgb, [[GIF|.gif]], [[JPEG|.jpg]], [[Portable Network Graphics|.png]], [[TIFF|.tiff]], .pic, [[BMP file format|.bmp]], [[DirectDraw Surface|.dds]], [[Truevision TGA|.tga]] and [[QuickTime File Format|quicktime]].

This module also provides I/O device abstraction. The other file-format loader plugins are registered with osgDB.

==== osgGA ====
This is a GUI abstraction library required for different platforms.

=== osgViewer ===
osgViewer Library provides a quick and easy way of [[Information visualization|visualizing]] the graphics scene. It is also a platform-independent abstraction for various [[window system]] interfaces.

==== osgProducer ====
The OSG is also shipped with a '''osgProducer''' which is just a platform-independent viewer supporting multiple graphic contexts and multi-threading.<ref>{{Cite web|last=Aylett|first=Ruth|title=Introduction to Open Scene Graph|url=https://www.macs.hw.ac.uk/~ruth/year4VEs/Slides10/L9.pdf|publisher=[[Heriot Watt University]]}}</ref><ref>{{Cite web|title=Introduction to the OpenSceneGraph|url=http://openscenegraph.sourceforge.net/documentation/OpenSceneGraph/doc/introduction.html|access-date=2021-07-05|website=openscenegraph.sourceforge.net}}</ref>

=== NodeKits ===
Project distribution also contains a variety of so-called ''NodeKits''. These are solutions of common problems and frequently used more advanced 3D application components and graphics algorithms. Among the most significant are

* osgAnimation — Skeletal models usage, animating and morphing.
* osgFX — Special effects and image postprocessing.
* osgManipulator — Interactive 3D scene manipulation.
* osgParticle — Advanced [[particle system]] usage.
* osgQt — Integration with [[Qt (framework)|Qt toolkit]] and incorporation of QtGUI elements into OSG applications.
* osgShadow — Framework for shadow rendering techniques.
* osgTerrain — Extensive [[terrain rendering]].
* osgText — Quality antialiased fonts, TrueType and FreeType font support.
* osgVolume — [[Volume rendering]] and volumetric data manipulation.
* osgWidget — Simple [[Graphical user interface|GUI]] creation.

==Reception and adoption==
OpenSceneGraph doesn't provide any functionality for higher "gaming" logic, it is a rendering-only tool. There are several full-scale [[Game engine|engines]] for [[computer games]] (or so-called ''[[serious games]]'') creation using OSG as a base of graphics rendering, the most common framework being [[Delta3D]].

There is a great variety of software products built on top of OpenSceneGraph; among others, [http://www.vterrain.org Virtual Terrain Project] and [http://www.viewtec.net ViewTec TerrainView]. List of OSG users contains companies as [[Boeing]], [[NASA]], [[FlightGear]], [[Norcontrol]] and many others.<ref name="Use Cases">{{Cite web|url=http://www.openscenegraph.com/index.php/gallery/use-cases|title=Use cases|website=www.openscenegraph.com}}</ref><ref name="Use Cases 2">{{Cite web |title=OpenSceneGraph |url=https://openscenegraph.github.io/openscenegraph.io/openscenegraph.io/ |access-date=13 March 2024 |website=openscenegraph.github.io |language=en}}</ref><ref name="VTP">{{Cite web|url=http://vterrain.org/|title=Virtual Terrain Project|website=vterrain.org}}</ref><ref name="TV">{{cite web |url=http://www.viewtec.net/index.php?page=products |title=ViewTec Inc. - Products |website=www.viewtec.net  |archive-url=https://web.archive.org/web/20090228064318/http://www.viewtec.net/index.php?page=products |archive-date=2009-02-28}}</ref><ref name="D3D">{{Cite web |date= |title=Delta3dengine 2023 |url=https://www.easd-design.com/delta3dengine/ |access-date=13 March 2024 |website=easd-design.com |language=}}</ref>

At the opensource community level, several projects have adopted OSG as a rendering backend:
* [[FlightGear]] (Flight Simulation software)
* [[OpenMW]] (Open-source engine recreation for [[Morrowind]])

OpenSceneGraph has received a javascript/WebGL implementation called [[OSG.JS]] that is used by many online 3D scene viewers including [[Sketchfab]] and [[Clara.io]].

A wrapping from C++ to javascript through Emscripten [[OGStudio]] is also currently developed.

Among other products that use OSG must be mentioned:
* [[Remo 3D]] OSG Scene Editor

==See also==
* [[OSG.JS]]
* [[OpenGL]]
* [[OGRE]]
* [[Delta3D]]
* [[Irrlicht Engine]]
* [[Crystal Space]]
* [[Visualization Library]]
* [[OpenSG]]
* [[ossimPlanet]]
* [[Grome]]
* [[Open Inventor]]
* [[Unity (game engine)]]

==References==
{{Reflist|30em}}

== External links ==
* {{URL|http://www.openscenegraph.org/}} - official website for the project
* [https://web.archive.org/web/20111011190138/http://openscenegraph.alphapixel.com/osg/downloads/free-openscenegraph-binary-downloads AlphaPixel OSG Binaries] - Windows, Mac and Linux x86 and x64 precompiled binaries.
* [http://code.google.com/p/sigmaosg/ SigmaOSG] - OpenSceneGraph Tutorials (contains all the prior OSGHelp material from retired OSGHelp site)
* [https://web.archive.org/web/20110508115302/http://programmingmatters.com/scenegraphs-and-openscenegraph-for-3d-software-development/ Scenegraphs and Openscenegraph for 3D Software Development]
* [http://www.opengl.org/sdk/libs/OpenSceneGraph/ OpenSceneGraph] - library information webpage on ''www.OpenGL.org'' (one of four promoted libraries)

[[Category:3D scenegraph APIs]]