Difference between revisions of "X3D Binary Compression Capabilities and Plans"

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Synopsis: Lots of work has been accomplished using X3D Compressed Binary Encoding standard for a wide variety of potential uses.
+
==Motivation==
X3D has an 80%-complete solution already available that meets various requirements for a general 3D transmission format.  Further improvements and standards-based partnerships are possible.
+
Following the strategy found in the [http://www.web3d.org/working-groups/x3d/compressed-binary-encoding-activity X3D Compressed Binary Encoding Activity], lots of work has already been accomplished using the X3D Efficient Binary Encoding (EBE) standard.
  
''In progress:'' We are building a draft 2013 Call For Contributions to further advance these technical capabilities for X3D.
+
X3D has numerous coherent approaches already available that meet author requirements for a general Web-based 3D transmission format.
 +
 
 +
We are combining Efficient XML Interchange (EXI) data compression with Fraunhofer streaming and geometry compression.  This new encoding will create dramatic new capabilities that provide full functional compatibility with existing X3D encodings in XML, ClassicVRML and the previous binary format.
 +
 
 +
We are now ready to demonstrate and standardize multiple interoperable improvements for a final standard.
 +
 
 +
==Strategy and Milestones, 2013-2017==
 +
* Annual.  We reviewed goals and developmental capabilities at the Web3D Conferences and SIGGRAPH in 2013, 2014 and (soon) 2015.
 +
* 2013. We accomplished our strategic goal to define X3D Compressed Binary Encoding (CBE) requirements and planned all steps.
 +
* 2014. We received multiple contributions for geometric compression and progressive streaming for X3D.
 +
* 2014. Efficient XML Interchange (EXI) is a fully approved W3C Recommendation with multiple implementations (both commercial and open source).
 +
* 2015. Decision: retain existing Compressed Binary Encoding (.x3db) for model stability, add Efficient Binary Encoding (.x3de) for improved capabilities.
 +
* 2015. All needed components are in hand.  Shape Resource Container (SRC) efforts ongoing.
 +
* 2016. Continued participation in EXI Working Group.  Need to review Call for Contributions, implementations and specification efforts.
 +
* 2017. SRC is aligned with glTF with implementations nearly ready to continue work. Consider comparing BLAST to SRC.
 +
* Target completion? With sufficient member contributions, we may be able to finish by the end of the year.
 +
 
 +
==Call For Contributions==
 +
X3D solutions currently support a wide range of author requirements.
 +
Further improvements and standards-based partnerships are possible for achieving broader industry interoperability.
 +
 
 +
The [http://www.web3d.org/working-groups/x3d/compressed-binary-encoding-activity X3D Compressed Binary Encoding Call For Contributions] to help accomplish these achievable goals has been released. We are seeking next-generation improvements that further advance the technical capabilities of the X3D Graphics International Standard.
 +
* [http://www.web3d.org/news-story/3d-graphics-compress-call-contributions Press release summary]
 +
 
 +
'''Prior work is essential, useful and relevant.'''
 +
* The first-generation [http://www.web3d.org/x3d/binary/X3dBinaryRFP.html X3D Compressed Binary Encoding Request For Proposals (RFP)] (currently unavailable) from August 2003 illustrates this steady evolution.
 +
* The first-generation process successfully created the current [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/X3D_Binary.html X3D Compressed Binary Encoding (CBE)] International Standard.
 +
'''All submitters must meet certain requirements prior to consideration.'''
 +
* The [http://www.web3d.org/realtime-3d/about/legal Intellectual Property Rights (IPR)] protections for X3D specification.
 +
* Patented technologies can be considered, but only when eventual use will be royalty free for X3D use (if eventually accepted).
 +
* Submitters can restrict access to patented submissions during member-only working group review, if desired.
  
 
== Existing Compression Usage for X3D and VRML97 ==
 
== Existing Compression Usage for X3D and VRML97 ==
 +
A solid foundation exists for continued progress.
 
* Approved ISO standard [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/X3D_Binary.html Compressed Binary Encoding (CBE) for X3D].
 
* Approved ISO standard [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/X3D_Binary.html Compressed Binary Encoding (CBE) for X3D].
 
** Based on ISO standard [http://fi.java.net Fast Infoset (FI)] for XML compression.
 
** Based on ISO standard [http://fi.java.net Fast Infoset (FI)] for XML compression.
Line 13: Line 44:
 
** This emerged as a common practice when gzip was originally used. No formal specification of .wrz or corresponding mime type was produced.
 
** This emerged as a common practice when gzip was originally used. No formal specification of .wrz or corresponding mime type was produced.
 
** Occasionally authors might also gzip .wrl files while retaining the .wrl file extension.
 
** Occasionally authors might also gzip .wrl files while retaining the .wrl file extension.
 +
 +
Multiple X3D compressed binary encoding (CBE) codebases exist for producing .x3db scenes under the existing standard. However, conformance interoperability between different implementations is not well tested.
 +
 +
'''Web3D will not formally advance a next-generation X3D binary compression format as a candidate standard until current interoperability has been satisfactorily demonstrated for the existing standard.'''
  
 
== Polygon Reduction and Geometric Compression ==
 
== Polygon Reduction and Geometric Compression ==
Line 18: Line 53:
 
* The X3D Compressed Binary Encoding defines extensible, repeatable [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#X3DCompressionDataFlow compression] and [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#X3DDecompressionDataFlow decompression] algorithms for [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#OverviewIntroduction data-flow production chains]. Multiple type-specific [http://www.web3d.org/files/specifications/19776-3/V3.1/Part03/EncodingOfFields.html field encoders] and geometric compression algorithms can be used in concert, but no specific geometric compression algorithms are referenced or required.
 
* The X3D Compressed Binary Encoding defines extensible, repeatable [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#X3DCompressionDataFlow compression] and [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#X3DDecompressionDataFlow decompression] algorithms for [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#OverviewIntroduction data-flow production chains]. Multiple type-specific [http://www.web3d.org/files/specifications/19776-3/V3.1/Part03/EncodingOfFields.html field encoders] and geometric compression algorithms can be used in concert, but no specific geometric compression algorithms are referenced or required.
 
* [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#X3DCanonicalForm X3D Canonicalization (C14N)] provides standardized formatting so that digital signatures are not thwarted by whitespace variations.
 
* [http://www.web3d.org/files/specifications/19776-3/V3.2/Part03/concepts.html#X3DCanonicalForm X3D Canonicalization (C14N)] provides standardized formatting so that digital signatures are not thwarted by whitespace variations.
Best practices:
+
Best practices and examples:
 
* [http://www.web3d.org/x3d/workgroups/cad CAD Distillation Filter (CDF)] technique allowing successive refinement of large X3D scenes into tighter X3D scenes.
 
* [http://www.web3d.org/x3d/workgroups/cad CAD Distillation Filter (CDF)] technique allowing successive refinement of large X3D scenes into tighter X3D scenes.
 
* A highly effective exemplar algorithm for [http://www.cs.unc.edu/~isenburg/research/asciicoder Coding Polygon Meshes as Compressable ASCII] is demonstrated in the [http://www.web3d.org/x3d/content/examples/Basic/ExperimentalBinaryCompression Experimental Binary Compression examples].
 
* A highly effective exemplar algorithm for [http://www.cs.unc.edu/~isenburg/research/asciicoder Coding Polygon Meshes as Compressable ASCII] is demonstrated in the [http://www.web3d.org/x3d/content/examples/Basic/ExperimentalBinaryCompression Experimental Binary Compression examples].
Line 24: Line 59:
 
* The [http://www2.hrp.no/vr/tools/chisel/install.htm Chisel VRML Optimisation Tool] has an excellent set of data-reduction tools for VRML that are worth repeating for X3D.
 
* The [http://www2.hrp.no/vr/tools/chisel/install.htm Chisel VRML Optimisation Tool] has an excellent set of data-reduction tools for VRML that are worth repeating for X3D.
 
* Multiple other [http://www.web3d.org/x3d/content/examples/X3dResources.html#Conversions conversion and translation tools] available with supporting capabilities.
 
* Multiple other [http://www.web3d.org/x3d/content/examples/X3dResources.html#Conversions conversion and translation tools] available with supporting capabilities.
 +
* Following submission of candidate technologies, we will build a table of 3D graphics compression benchmark results, providing a full comparison of existing tools (compression ratio, computational complexity, memory usage, etc.)
 +
* MPEG4 capabilities are welcome, if IPR prerequisites are met. Discussion to date has indicated that Royalty Free (RF) solutions are not available.
 +
* Related efforts reported in academic papers and Web3D conferences need to be reviewed and reflected here
  
 
== Data-Centric Binary Encodings ==
 
== Data-Centric Binary Encodings ==
 +
The X3D Compressed Binary Encoding (CBE) uses the ISO Fast Infoset (FI) standard to compress XML information, which is how the CBE maintains equivalent expressive power with other X3D scene encodings.
 
* Plan to add a further-improved X3D Compressed Binary Encoding using now-approved W3C Recommendation for [http://www.w3.org/TR/exi/ Efficient XML Interchange (EXI)].
 
* Plan to add a further-improved X3D Compressed Binary Encoding using now-approved W3C Recommendation for [http://www.w3.org/TR/exi/ Efficient XML Interchange (EXI)].
 
* Web3D contributed to [http://www.w3.org/XML/EXI/ EXI working group] and [http://www.w3.org/XML/Binary XML Binary Characterization working group] efforts.
 
* Web3D contributed to [http://www.w3.org/XML/EXI/ EXI working group] and [http://www.w3.org/XML/Binary XML Binary Characterization working group] efforts.
Line 32: Line 71:
 
** Relevant example scenes maintained as part of [http://www.web3d.org/x3d/content/examples/Basic/Security X3D Basic Examples Archive - Security].
 
** Relevant example scenes maintained as part of [http://www.web3d.org/x3d/content/examples/Basic/Security X3D Basic Examples Archive - Security].
 
* These capabilities meets most needs of digital authors for digital rights management (DRM).
 
* These capabilities meets most needs of digital authors for digital rights management (DRM).
 +
* '''Review Open Geospatial Consortium (OGC) requirements to determine whether additional optimizations might improve the already-excellent coverage of geospatial datasets'''
 +
** Also explore the possibility that additional compression algorithms may show better efficiency for geospatial datasets
 +
* Following submission of candidate technologies, we will build a table of data compression benchmark results, providing a full comparison of existing tools (compression ratio, computational complexity, memory usage, etc.)
  
 
== Network Streaming ==
 
== Network Streaming ==
 
* Multiple capabilities are already available in X3D for flexible network transmission.
 
* Multiple capabilities are already available in X3D for flexible network transmission.
 
** Anchor, Inline, LOD, LoadSensor, Script and Prototype nodes support successive retrieval of content once initial model is displayed.
 
** Anchor, Inline, LOD, LoadSensor, Script and Prototype nodes support successive retrieval of content once initial model is displayed.
* TODO: Willing to consider further addition of progressive-mesh geometric streaming technologies, perhaps by a public Call for Contributions. Note however that an effective progressive-mesh approach is likely dependent on the availability of a corresponding mesh compression algorithm.
+
* Progressive-mesh geometric streaming technologies hold definite interest. Mesh-compression algorithms that can be applied to existing X3D polygonal data will be the most valuable.
** For example, the original August 2003 [http://www.web3d.org/x3d/binary/X3dBinaryRFP.html X3D Compressed Binary Encoding Request For Proposals (RFP)].
+
* Need to demonstrate whether http/https and local-file url retrieval are sufficient for a network protocol for use cases of interest.
* [http://www.web3d.org/realtime-3d/about/legal Intellectual Property Rights (IPR)] protections for X3D specification.
+
** Other network protocols (Web sockets, P2P channels, etc.) might be possible or needed, but only if security restrictions and implementation/deployment can be handled satisfactorily.
** Patented technologies can be considered, but only when eventual use will be royalty free for X3D use (if eventually accepted).
+
* Javascript Object Notation (JSON) might be suitable for simple streaming of X3D scene-graph data via Script node or external HTML page, which can be useful for progressive mesh and other incremental network-update approaches.
** Submitters can restrict access to patented submissions during member-only working group review, if desired.
+
** Support in clients and servers is becoming widely available.
 +
** JSON might have other uses as well, see Khronos work on [https://github.com/KhronosGroup/glTF/blob/master/specification/README.md Collada2JSON and glTF]. This is an active area of work.
  
* TODO: Use cases and test examples can demonstrate whether http/https and local-file url retrieval are sufficient for a network protocol.
+
== Resource Bundling ==
** Other network protocols (Web sockets, P2P channels, etc.) might be possible, but only if security restrictions can be handled satisfactorily.
+
* Mechanisms for bundling multiple files (e.g. X3D scene, Inlined subscenes, image files, audio and video files, etc.) into a single archive file will be considered.
** Javascript Object Notation (JSON) might be suitable for simple streaming of X3D scene-graph data via Script node or external HTML page, which can be useful for progressive mesh and other incremental network-update approaches.
+
* Similar bundling capabilities are emerging for uncompressed X3D scenes embedded within HTML pages.
** JSON might have other uses as well, see Khronos work on [https://github.com/KhronosGroup/glTF/blob/master/specification/README.md Collada2JSON and glTF].
+
* Benefits support improved deployability and archivability of X3D content
** Further investigation needed.
+
* Technical issues include .gzip versus .zip, bundling of metadata (demonstrated by Java .jar and .war formats), etc.
 +
* The [http://freewrl.sourceforge.net FreeWRL project] is implementing and exploring possible approaches to this challenge
  
== X3D Implementations ==
+
== X3D Implementations and Benchmark Testing==
 
The following tools implement the X3D Compressed Binary Encoding (CBE) standard.
 
The following tools implement the X3D Compressed Binary Encoding (CBE) standard.
 
* Two independent open-source implementations available.
 
* Two independent open-source implementations available.
Line 57: Line 101:
 
** [[Tool support for X3D components]]
 
** [[Tool support for X3D components]]
 
* Several thousand [http://www.web3d.org/x3d/content/examples/X3dResources.html#Examples X3D Examples] are available in ''.x3db'' form, encoded by Xj3D.
 
* Several thousand [http://www.web3d.org/x3d/content/examples/X3dResources.html#Examples X3D Examples] are available in ''.x3db'' form, encoded by Xj3D.
** TODO: Plan to similarly automate conversions and comparisons, using both Xj3D and XIOT, for cross-check interoperability and validation testing.
+
 
 +
Existing assets can be improved to establish a comprehensive X3D compression benchmark suite.
 +
* Such a suite can facilitate testing of new contributed capabilities.
 +
* We plan to automate conversions and comparisons, using Xj3D XIOT and other submissions, for cross-check interoperability and validation testing.
 +
* It will be easy to automate such a suite using our many example scenes and the already-existing nightly build (continuous integration) processes.
 +
* This will automate the production of results summarized in the compression performance tables constructed as part of the call for technologies.
 +
* Primary metrics are file size, conversion speed and memory requirements. Visual inspection of result quality will also be provided.
  
 
== Looking Ahead ==
 
== Looking Ahead ==
* Web3D's X3D and [http://www.web3d.org/realtime-3d/computer-aided-design-cad CAD] Working Groups each have member commitments to pursue this continued innovative work in 2013.
+
'''Work in Progress.'''
* TODO: An open workshop on 3D Transmission Formats might be a thorough way to compare candidate technologies to complete these capabilities.
+
* Web3D's X3D and [http://www.web3d.org/realtime-3d/computer-aided-design-cad CAD] Working Groups each have member commitments to pursue this continued innovative work during 2013-2014.
* Consider common, sharable technical strategies with MPEG-4 and Collada.
+
* We are always keen to consider common, sharable technical strategies with other industry standards. Web3D Consortium has been waiting for a response from The Khronos Group and MPEG standards SC 29 committee since a joint meeting at SIGGRAPH conference August 2012. To date, formal MPEG4 communications have indicated that a royalty-free solution is not possible. Khronos work appears likely but royalty requirements and design compatiblity remains unclear.
 +
 
 +
'''Meetings.'''
 +
* The first weekly X3D Working Group meeting of each month is dedicated to an X3D Futures discussion, including X3D Binary Compression Capabilities and Plans.
 +
* The [http://web3d2013.org Web3D 2013 conference] included an open meeting on 3D Transmission Formats, to be held Wednesday 19 June 2013 in San Sebastian Spain.
 +
** Responses to the [http://www.web3d.org/realtime-3d/working-groups/x3d/compressed-binary/x3d-compressed-binary-encoding-call-contributions X3D Binary Compression Call for Contributions] will be reviewed and candidate technologies will be discussed.
 +
** Inquiries and presentation requests can be sent to the [http://www.web3d.org/realtime-3d/page/contact/x3d-chairs X3D Working Group Cochairs].  
 +
* We further plan to meet publicly at the annual SIGGRAPH Conferences.
 +
 
 +
'''Adding example Use Cases will help evaluate the value of each contribution.'''
 +
* Technical requirements are important for performing comparative measurements, but sometimes they don't tell the whole story.
 +
* Also defining work-flow authoring requirements for compressed X3D scenes is helpful, providing useful criteria for evaluating technical capabilities. Use cases enable us to determine whether each possible improvement effectively meets a declared need.
 +
* X3D authors are asked to help us document common workflow practices. We will extend the requirements to build an updated set of use cases to help evaluation. The emerging next-generation standard is being designed to provide the best possible value to Web authors, users, and software developers.
 +
* Once the basic framework updated, we will ask each working group to identify special case examples for demonstrating value, avoiding problems, or further optimization.
 +
 
 +
'''Follow-on work'''
 +
* Provide an additional [http://web3d.org/wiki/index.php/X3D_MIME-Type X3D MIME Type] submission to IANA
 +
* Update references in all other X3D specifications
 +
 
 +
== Contributions Received ==
 +
 
 +
* [http://web3d.org/wiki/images/7/77/Mesh_encodings_for_X3DOM_-_Recent_Advances_-_ML_-_12NOV2013.pdf Mesh encodings for X3DOM - Recent Advances] Fraunhofer provided a comprehensive list of proposed improvements on an X3D Working Group teleconference, 12 November 2013
 +
** Further detail available at [http://www.x3dom.org/pop | X3DOM Progressively Ordered Primitives (POP)]]

Latest revision as of 17:32, 26 March 2017

Motivation

Following the strategy found in the X3D Compressed Binary Encoding Activity, lots of work has already been accomplished using the X3D Efficient Binary Encoding (EBE) standard.

X3D has numerous coherent approaches already available that meet author requirements for a general Web-based 3D transmission format.

We are combining Efficient XML Interchange (EXI) data compression with Fraunhofer streaming and geometry compression. This new encoding will create dramatic new capabilities that provide full functional compatibility with existing X3D encodings in XML, ClassicVRML and the previous binary format.

We are now ready to demonstrate and standardize multiple interoperable improvements for a final standard.

Strategy and Milestones, 2013-2017

  • Annual. We reviewed goals and developmental capabilities at the Web3D Conferences and SIGGRAPH in 2013, 2014 and (soon) 2015.
  • 2013. We accomplished our strategic goal to define X3D Compressed Binary Encoding (CBE) requirements and planned all steps.
  • 2014. We received multiple contributions for geometric compression and progressive streaming for X3D.
  • 2014. Efficient XML Interchange (EXI) is a fully approved W3C Recommendation with multiple implementations (both commercial and open source).
  • 2015. Decision: retain existing Compressed Binary Encoding (.x3db) for model stability, add Efficient Binary Encoding (.x3de) for improved capabilities.
  • 2015. All needed components are in hand. Shape Resource Container (SRC) efforts ongoing.
  • 2016. Continued participation in EXI Working Group. Need to review Call for Contributions, implementations and specification efforts.
  • 2017. SRC is aligned with glTF with implementations nearly ready to continue work. Consider comparing BLAST to SRC.
  • Target completion? With sufficient member contributions, we may be able to finish by the end of the year.

Call For Contributions

X3D solutions currently support a wide range of author requirements. Further improvements and standards-based partnerships are possible for achieving broader industry interoperability.

The X3D Compressed Binary Encoding Call For Contributions to help accomplish these achievable goals has been released. We are seeking next-generation improvements that further advance the technical capabilities of the X3D Graphics International Standard.

Prior work is essential, useful and relevant.

All submitters must meet certain requirements prior to consideration.

  • The Intellectual Property Rights (IPR) protections for X3D specification.
  • Patented technologies can be considered, but only when eventual use will be royalty free for X3D use (if eventually accepted).
  • Submitters can restrict access to patented submissions during member-only working group review, if desired.

Existing Compression Usage for X3D and VRML97

A solid foundation exists for continued progress.

  • Approved ISO standard Compressed Binary Encoding (CBE) for X3D.
  • Optional, alternative gzip compression and MIME Type definitions for X3D.
  • Optional, alternative gzip compression for VRML97.
    • Original compression technique of applying gzip to .wrl compressed VRML97 files was called .wrz.
    • This emerged as a common practice when gzip was originally used. No formal specification of .wrz or corresponding mime type was produced.
    • Occasionally authors might also gzip .wrl files while retaining the .wrl file extension.

Multiple X3D compressed binary encoding (CBE) codebases exist for producing .x3db scenes under the existing standard. However, conformance interoperability between different implementations is not well tested.

Web3D will not formally advance a next-generation X3D binary compression format as a candidate standard until current interoperability has been satisfactorily demonstrated for the existing standard.

Polygon Reduction and Geometric Compression

Formal specifications:

Best practices and examples:

  • CAD Distillation Filter (CDF) technique allowing successive refinement of large X3D scenes into tighter X3D scenes.
  • A highly effective exemplar algorithm for Coding Polygon Meshes as Compressable ASCII is demonstrated in the Experimental Binary Compression examples.
  • Multiple CAD Distillation Filter (CDF) algorithms implemented in Xj3D and X3D-Edit as open-source.
  • The Chisel VRML Optimisation Tool has an excellent set of data-reduction tools for VRML that are worth repeating for X3D.
  • Multiple other conversion and translation tools available with supporting capabilities.
  • Following submission of candidate technologies, we will build a table of 3D graphics compression benchmark results, providing a full comparison of existing tools (compression ratio, computational complexity, memory usage, etc.)
  • MPEG4 capabilities are welcome, if IPR prerequisites are met. Discussion to date has indicated that Royalty Free (RF) solutions are not available.
  • Related efforts reported in academic papers and Web3D conferences need to be reviewed and reflected here

Data-Centric Binary Encodings

The X3D Compressed Binary Encoding (CBE) uses the ISO Fast Infoset (FI) standard to compress XML information, which is how the CBE maintains equivalent expressive power with other X3D scene encodings.

  • Plan to add a further-improved X3D Compressed Binary Encoding using now-approved W3C Recommendation for Efficient XML Interchange (EXI).
  • Web3D contributed to EXI working group and XML Binary Characterization working group efforts.
  • Design includes compatibility with CDF techniques, XML Encryption, and XML Digital Signature for author authentication.
  • These capabilities meets most needs of digital authors for digital rights management (DRM).
  • Review Open Geospatial Consortium (OGC) requirements to determine whether additional optimizations might improve the already-excellent coverage of geospatial datasets
    • Also explore the possibility that additional compression algorithms may show better efficiency for geospatial datasets
  • Following submission of candidate technologies, we will build a table of data compression benchmark results, providing a full comparison of existing tools (compression ratio, computational complexity, memory usage, etc.)

Network Streaming

  • Multiple capabilities are already available in X3D for flexible network transmission.
    • Anchor, Inline, LOD, LoadSensor, Script and Prototype nodes support successive retrieval of content once initial model is displayed.
  • Progressive-mesh geometric streaming technologies hold definite interest. Mesh-compression algorithms that can be applied to existing X3D polygonal data will be the most valuable.
  • Need to demonstrate whether http/https and local-file url retrieval are sufficient for a network protocol for use cases of interest.
    • Other network protocols (Web sockets, P2P channels, etc.) might be possible or needed, but only if security restrictions and implementation/deployment can be handled satisfactorily.
  • Javascript Object Notation (JSON) might be suitable for simple streaming of X3D scene-graph data via Script node or external HTML page, which can be useful for progressive mesh and other incremental network-update approaches.
    • Support in clients and servers is becoming widely available.
    • JSON might have other uses as well, see Khronos work on Collada2JSON and glTF. This is an active area of work.

Resource Bundling

  • Mechanisms for bundling multiple files (e.g. X3D scene, Inlined subscenes, image files, audio and video files, etc.) into a single archive file will be considered.
  • Similar bundling capabilities are emerging for uncompressed X3D scenes embedded within HTML pages.
  • Benefits support improved deployability and archivability of X3D content
  • Technical issues include .gzip versus .zip, bundling of metadata (demonstrated by Java .jar and .war formats), etc.
  • The FreeWRL project is implementing and exploring possible approaches to this challenge

X3D Implementations and Benchmark Testing

The following tools implement the X3D Compressed Binary Encoding (CBE) standard.

Existing assets can be improved to establish a comprehensive X3D compression benchmark suite.

  • Such a suite can facilitate testing of new contributed capabilities.
  • We plan to automate conversions and comparisons, using Xj3D XIOT and other submissions, for cross-check interoperability and validation testing.
  • It will be easy to automate such a suite using our many example scenes and the already-existing nightly build (continuous integration) processes.
  • This will automate the production of results summarized in the compression performance tables constructed as part of the call for technologies.
  • Primary metrics are file size, conversion speed and memory requirements. Visual inspection of result quality will also be provided.

Looking Ahead

Work in Progress.

  • Web3D's X3D and CAD Working Groups each have member commitments to pursue this continued innovative work during 2013-2014.
  • We are always keen to consider common, sharable technical strategies with other industry standards. Web3D Consortium has been waiting for a response from The Khronos Group and MPEG standards SC 29 committee since a joint meeting at SIGGRAPH conference August 2012. To date, formal MPEG4 communications have indicated that a royalty-free solution is not possible. Khronos work appears likely but royalty requirements and design compatiblity remains unclear.

Meetings.

  • The first weekly X3D Working Group meeting of each month is dedicated to an X3D Futures discussion, including X3D Binary Compression Capabilities and Plans.
  • The Web3D 2013 conference included an open meeting on 3D Transmission Formats, to be held Wednesday 19 June 2013 in San Sebastian Spain.
  • We further plan to meet publicly at the annual SIGGRAPH Conferences.

Adding example Use Cases will help evaluate the value of each contribution.

  • Technical requirements are important for performing comparative measurements, but sometimes they don't tell the whole story.
  • Also defining work-flow authoring requirements for compressed X3D scenes is helpful, providing useful criteria for evaluating technical capabilities. Use cases enable us to determine whether each possible improvement effectively meets a declared need.
  • X3D authors are asked to help us document common workflow practices. We will extend the requirements to build an updated set of use cases to help evaluation. The emerging next-generation standard is being designed to provide the best possible value to Web authors, users, and software developers.
  • Once the basic framework updated, we will ask each working group to identify special case examples for demonstrating value, avoiding problems, or further optimization.

Follow-on work

  • Provide an additional X3D MIME Type submission to IANA
  • Update references in all other X3D specifications

Contributions Received