出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2012/04/11 18:09:33」(JST)
Virtual Reality Modeling Language (仮想現実モデリング言語、VRML) は、3次元の物体に関する情報を記述するためのファイルフォーマット。WWW上で利用されることを前提に設計された。
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ファイル形式はテキストファイル(コンパイルが不要)であり、ヘッダ、コメント、ノード(フィールド)、プロトタイプ、ルートの5つの要素から構成される。 3Dポリゴンの頂点および線の座標、ポリゴンや色や画像によるテクスチャー、光源による明るさなどを指定できる。 また、URL指定によってインターネット上の別の場所にある画像やVRMLファイルを指定できる。 アニメーションや光源、視点の設定などといったインタラクティブな効果も設定でき、一種の仮想空間を構築できる。 さらに、Scriptノードを使って、Java・JavaScriptなどのプログラミング言語と連携させた動作を行うことも可能である。
VRMLファイルは「ワールド」とも呼ばれ、.wrl という拡張子が付く(たとえば bird.wrl)。VRMLファイルを閲覧するVRMLブラウザには、Cortona VRML Client [1]、blaxxun Contact [2]、PivoronPlayer [3] などがある。 また、VRMLファイル自体はテキスト形式だが、座標値などの3Dデータを多く含み、ファイル容量が大きくなるため、gzipを使った圧縮が行われる場合も多い。 たいていの3次元モデリングツールには、VRML形式での保存機能が付いている。
このフォーマットの開発を推進するためにWeb3Dコンソーシアムが設立され、規格についての議論などが行われている。
VRMLの最初のバージョン(通称VRML 1.0)は1994年11月に制定された。 このバージョンではSGI社により開発されていたOpen Inventorとよばれるツールのファイルフォーマットに良く似た仕様として制定された。 その後、インタラクティブな動きなどの新しい機能を追加したVRML 97 (ISO/IEC DIS 14772-1, 通称VRML 2.0) 仕様が策定された。 現在では、VRMLと呼ぶ場合にはこのVRML 2.0を指すことが多い。
VRML1.0の制定以降、3次元空間を容易に記述できるという点から注目され、Webブラウザからそのまま使えるさまざまなプラグインも提供され、普及も進んだ。 しかし、VRMLの表現能力の限界やモデリングツールの少なさ、操作の難しさなどから、しだいにあまり使われなくなっている。
VRMLの表現能力の限界などから、次世代の仕様としてXMLベースのX3Dを一から作成することとなった。
Filename extension | .wrl (plain).wrz (compression) |
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Internet media type | model/vrml |
Latest release | 2.0 |
Type of format | 3D computer graphics |
Extended from | Labyrinth |
Standard(s) | ISO/IEC 14772-1:1997 |
Website | www.web3d.org/x3d/vrml |
VRML (Virtual Reality Modeling Language, pronounced vermal or by its initials, originally—before 1995—known as the Virtual Reality Markup Language) is a standard file format for representing 3-dimensional (3D) interactive vector graphics, designed particularly with the World Wide Web in mind. It has been superseded by X3D.[1]
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VRML is a text file format where, e.g., vertices and edges for a 3D polygon can be specified along with the surface color, UV mapped textures, shininess, transparency, and so on.[2] URLs can be associated with graphical components so that a web browser might fetch a webpage or a new VRML file from the Internet when the user clicks on the specific graphical component. Animations, sounds, lighting, and other aspects of the virtual world can interact with the user or may be triggered by external events such as timers. A special Script Node allows the addition of program code (e.g., written in Java or JavaScript (ECMAScript)) to a VRML file.
VRML files are commonly called "worlds" and have the *.wrl extension (for example island.wrl). Although VRML worlds use a text format, they may often be compressed using gzip so that they transfer over the internet more quickly (some gzip compressed files use the *.wrz extension). Many 3D modeling programs can save objects and scenes in VRML format.
The Web3D Consortium has been formed to further the collective development of the format. VRML (and its successor, X3D), have been accepted as international standards by the International Organization for Standardization (ISO).
The first version of VRML was specified in November 1994. This version was specified from, and very closely resembled, the API and file format of the Open Inventor software component, originally developed by SGI. The current and functionally complete version is VRML97 (ISO/IEC 14772-1:1997). VRML has now been superseded by X3D (ISO/IEC 19775-1)
The term VRML was coined by Dave Raggett in a paper called “Extending WWW to support Platform Independent Virtual Reality”[3] submitted to the First World Wide Web Conference[4] in 1994, and first discussed at the WWW94 VRML BOF established by Tim Berners-Lee, where Mark Pesce presented the Labyrinth demo he developed with Tony Parisi[5] and Peter Kennard.[6] In October 1995, at Internet World, Template Graphics Software (TGS) demonstrated a 3D/VRML plug-in for the beta release of Netscape 2.0 by Netscape Communications.[7]
In 1997, a new version of the format was finalized, as VRML97 (also known as VRML2 or VRML 2.0), and became an ISO standard. VRML97 was used on the Internet on some personal homepages and sites such as "CyberTown", which offered 3D chat using Blaxxun Software. The format was championed by SGI's Cosmo Software; when SGI restructured in 1998 the division was sold to Platinum Technologies, which was then taken over by Computer Associates, which did not develop or distribute the software. To fill the void a variety of proprietary Web 3D formats emerged over the next few years, including Microsoft Chrome and Adobe Atmosphere, neither of which is supported today. VRML's capabilities remained largely the same while realtime 3D graphics kept improving. The VRML Consortium changed its name to the Web3D Consortium, and began work on the successor to VRML—X3D.[8]
SGI ran a web site at vrml.sgi.com on which was hosted a string of regular short performances of a character called "Floops" who was a VRML character in a VRML world. Floops was a creation of a company called "Protozoa".[9][10]
H-Anim is a standard for animated Humanoids, which is based around VRML, and later X3D. The initial version 1.0 of the H-Anim standard was scheduled for submission at the end of March 1998.[citation needed]
VRML provoked much interest but has never seen much serious widespread use.[11] One reason for this may have been the lack of available bandwidth.[original research?] At the time of VRML's popularity, a majority of users, both business and personal, were using slow dial-up internet access. This had the unfortunate side effect of having users wait for extended periods of time only to find a blocky, ill-lit room with distorted text hanging in seemingly random locations.[citation needed]
VRML experimentation was primarily in education and research where an open specification is most valued.[citation needed] It has now been re-engineered as X3D. The MPEG-4 Interactive Profile (ISO/IEC 14496) was based on VRML[citation needed] (now on X3D), and X3D is largely backward-compatible with it. VRML is also widely used as a file format for interchange of 3D models, particularly from CAD systems.[12]
A free cross-platform runtime implementation of VRML is available in OpenVRML. Its libraries can be used to add both VRML and X3D support to applications, and a GTK+ plugin is available to render VRML/X3D worlds in web browsers.
In a September 17, 1998 Computergram International essay, "VRML Versus Chromeffects: Microsoft Replies", Rachel Chalmers sharply criticized VRML as having "no integration with HTML", whereas "ChromEffects is based on 56 multimedia XML tags".[13][14] She did not criticize X3D (though extended from VRML as well as XML), because X3D already had this integration. However, VRML survived Chromeffects, canceled in November 1998.[15]
In the 2000s, many companies like Bitmanagement improved the quality level of virtual effects in VRML to the quality level of DirectX 9.0c, but at the expense of using proprietary solutions. All main features like game modeling are already complete. They include multi-pass render with low level setting for Z-buffer, BlendOp, AlphaOp, Stencil,[16] Multi-texture,[17] Shader with HLSL and GLSL support,[18] realtime Render To Texture, Multi Render Target (MRT) and PostProcessing.[19] Many demos shows that VRML already supports lightmap, normalmap, SSAO, CSM and Realtime Environment Reflection along with other virtual effects.[20]
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