Registration of media type model/x3d+XXX (Revised 09.02.01)

[Leonard Daly]

I wish to thank everyone for their comments on the proposed X3D MIME 
types (model/x3d+xxx). We have considered your comments and revised our 
submission based on those comments. All of the comments were concerned 
with the various subtypes.

 From our perspective, it seems that the consensus is to use x3d-vrml 
for the ClassicVRML encoding. x3d+xml. We have made that change. x3d+xml 
was acceptable from previous use. We made a change to the binary 
encoding. It was x3d+binary. After review of the other MIME types 
approved and that our encoding algorithm uses  FastInfoSet compression, 
we have changed the MIME subtype for the binary encoding to 
x3d+fastinfoset. This appears to be compatible with the existing subtype 
of soap+fastinfoset 
(http://www.iana.org/assignments/media-types/application/soap+fastinfoset).

Please note that the reference X3D specifications do not contain these 
revisions. The specifications will be updated after they are approved.

Again we welcome comments and suggestions.

Thank you,

    Leonard Daly
    X3D Working Group Co-Chair

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Type name: model


Subtype names:
x3d-vrml
x3d+xml
x3d+fastinfoset


Required parameters:
None


Optional parameters:
None


Encoding considerations:
This application represents the different MIME types used for three
different encodings of the X3D ISO standard (see [1]). The standard
defines an abstract information structural representation, for which
several file formats are available. These formats are currently defined
to be:

VRML-Classic: (old-style curly brace format of the VRML97 ISO standard).
UTF-8 (8-bit text) is to be supported. The recently introduced UTF-8 BOM
cannot be supported by definition of the specification.

XML: Encoding requirements as per the XML standards.

Binary: (Effectively a binary XML encoding scheme based on the outcome
of the W3C binary XML working group process). Still a work in progress
and standardisation is not yet complete.

Each content type may have an addition Content-Encoding to indicate
whether the content has been compressed using GZIP in addition to the
basic textual encoding. This is also indicated by modifying each file
extension with the character "z". For example, the plaintext
VRML-encoded file format would use the extension ".x3dv", and if
compressed using GZIP uses the extension ".x3dvz"


Security considerations:
Scripting is defined as being available for the specification. Two
languages are defined: Java and ECMAScript. Each scripting language is
controlled by its local security model. As the content may run in many
different situations, the X3D specification does not impose specific
security policies. For example, some standalone applications will want
to directly interact with the local file system, network or database,
while others that run in a web browser would use the web-browser's
security model.


Interoperability considerations:
The definition of the file format is maintained by the Web3d Consortium
(http://www.web3d.org) and published through the ISO process. Several
revisions of the specification have been made and it continues to be
made. All revisions use the same MIME type definitions, and are
backwards compatible internally and structurally. In addition, each of
the file format encodings may be losslessly transformed between each
other.


Published specification:
All revisions of the X3D specification can be found here:
http://www.web3d.org/x3d/specifications/

Several revisions of each specification exist. The abstract
specification is ISO/IEC 19775:2004. The individual file formats, which
also specify the matching MIME types, are parts of the ISO/IEC 19777
specification.


Applications that use this media type:
There are well over 20 - both browsers, exporters and importers.


Additional information:


Magic number(s):
x3d-vrml: "#X3D"
x3d+xml: Use XML's specification
x3d+fastinfoset: "#X3D"

File extension(s):
x3d-vrml: .x3dv, .x3dvz
x3d+xml: .x3d, .x3dz
x3d+fastinfoset: .x3db

Macintosh file type code(s):


Person & email address to contact for further information:
Leonard Daly (X3D Working Group Co-Chair) Leonard.Daly at realism.com
Alan Hudson (Web3d Consortium President) giles at yumetech.com


Intended usage:
COMMON


Restrictions on usage:
None


Author:
The Web3D Consortium


Change controller:
The Web3D Consortium


The X3D standard is a continuation of the VRML standard that is defined
in RFC2077. As part of this work, several large modifications were made
to the file format and specification. The basic premise for the
specification continues the VRML philosophy. The MIME types and file
extensions were changed to indicate this modified standard.
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-- 
+--------
| Leonard Daly
| Internet Solutions, eBusiness Specialist http://realism.com/
| LA ACM SIGGRAPH, Electronic Services Chair
| X3D Book: http://x3dGraphics.com
+------------------------------