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Shout3D™ 1.0 - User Guide

File Formats and File Conversion

This file contains the following sections:

The four formats

Shout3D applets can read and display 4 different file formats:

  1. Uncompressed VRML97 files (.wrl extension)
  2. Compressed VRML97 files (.wrlz or usually also .wrl extension)
  3. Uncompressed Shout3d files (.s3d extension)
  4. Compressed Shout3d files (.s3z extension)

Shout3D will not read all existing VRML97 files. Those containing Script nodes and PROTO nodes are unreadable by Shout3D. All other files should read and load successfully, although some information will be lost. For an exhaustive description of which VMRL97 features are unsupported, click here.

Browser limitations

Compressed files are smaller, hence they take less time to download off of a server. So, all things being equal, it would always be preferable to serve compressed files. However, not all browsers can read compressed files.

Specify both a compressed and uncompressed file

Because of browser limitations, Shout3D provides a way to specify two files, a compressed one and an uncompressed one. The Shout3DWizard will do this automatically for you, but if you are hand editing your html files, you'll need to specify these as two separate applet parameters, one called "src" and one called "gzip_src" (click here for more info about the applet parameters).

Browsers that can read compressed files will fetch and read the "gzip_src" file, while other browsers will automatically fetch the regular "src" file.

VRML97 vs. Shout3D format

In most cases, it doesn't really matter which file format you choose. The two are quite similar. VRML97 is more "pretty printed" and easier to edit, while Shout3D's format is a bit more compact.

Also, Shout3D lets you create new node types and add them to your files (see the Pyramid demo for an example of this). Once you've added an instance of a node like Pyramid to your file, it will no longer read into VRML-only browsers like CosmoPlayer. So you should switch to the .s3d format whenever you use new node classes that you create.

Converting with the Shout3DWizard

The Shout3DWizard allows you to select VRML files, convert them, and write them out using a point-and-click interface. Click here for more information.

Converting with vrml2tos3d

The Shout3DWizard actually employs another, smaller program called vrml2tos3d when it converts files. This little program is good to know about if you prefer to work from a command line prompt or through batch files. The following describes its usage:

vrml2tos3d command-line arguments

Windows users only:
vrml2tos3d.exe [ options ] source [ destination ]
All users:
java vrml2tos3d [ options ] source [ destination ]
options: Command-line options.
source: VRML source file.
destination: Shout3D destination file.

vrml2tos3d options

-z Creates a gzipped .s3z file if JDK 1.1 or higher is present, in addition to the uncompressed .s3d file which is always created.

vrml2tos3d description

Creates an .s3d file with the specified destination name/path (as well as a gzipped .s3z file, if JDK 1.1 or higher is present and the -z option is given) from the specified .wrl source file. If no destination is given, the resulting destination file(s) are placed in the same directory as the .wrl source file.

On a Microsoft Windows system, a .wrl file can also be dragged and dropped onto vrml2tos3d.exe, which is equivalent to

vrml2tos3d.exe -z source

That is, the destination directory is the same as the source directory, and a gzipped .s3z file will be created if possible.

A note about the pw VRML parser

The converter utilizes the pw VRML parser, available from http://www.iicm.edu/vrwave/pw. It is used here under the terms of the GNU Lesser General Public License (see http://www.gnu.ai.mit.edu/copyleft/lesser.html ).The source code for the pw parser is included within the Shout3D_converter directory.


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