VRML 2.0

Converting to VRML 2.0

VRML 2.0 Translator

Special Features

• Cameras are converted to VRML2.0 Viewpoints.
• Ambient Lights are converted to a VRML point light with ambient properties.
• Per-vertex normals and texture coordinates (if desired).
• Material animation is converted.
• Animation is converted intelligently (only dynamic objects have animation information).
• Initial navigation mode can be specified in the translator.
• Double-sided/single-sided setting (in Render stats) is converted for groups.

Limitations

• Does not support VRML2.0 embedded textures.

Installing

The VRML translator does not require any installation.

Using the VRML2.0 Translator

Running the VRML Translator

There are two ways to run the VRML translator:

• If you have the MakeGame window open, choose VRML2 from the list of translators. Set the options in the MakeGame window, then click Go.
• Choose ExportVRML2 from the File menu. To get options similar to the MakeGame window, choose FileExportVRML2 .

GUI

On - use the VRML 2 translator's graphical user interface.

Off - Use the saved settings from the last time you clicked Save in the VRML 2 Translator window (do not open the graphical user interface).

Reload DSO

ON - unload the translator after each use.

OFF - keep the translator in memory for multiple runs.

Options

This text box not used. It is included for any command line options that might be added in the future. To set options of the VRML 2 translator, use the translator's graphical user interface.

Export Dir

The directory in which to put converted VRML files.

Options

Use this window to set the options described below, then click Go to start converting.

Main Controls

Go

Start the conversion.

During conversion, this button changes to Abort. Click it to stop the conversion.

Exit

Close the translator window.

Text Section

Type a text comment for the scene.

Animation Section

Update

The text at the top of this section shows the frames of animation available for export. If you add frames while the translator window is open, this number will be inaccurate. Click Update to update the frame count.

Start Frame

End Frame

start and end frames of animation to convert.

Frames per sec

intended playback speed of the converted animation.

Animate...

choose whether to animate transformations, materials, and lights.

View frames

show the animation frames in the Alias view windows as you export them.

Hierarchy Section

World

do not export hierarchy (all vertices use world space).

Flat

one level of hierarchy: transformations use world space, vertices use local space.

Full

export the full dag tree hierarchy: transformations and vertices use local space.

Navigator Section

These settings control the initial set-up of the VRML browser when it opens the .wrl file:

Viewer

the initial type of navigation.

Headlight

the viewer will cast light on the scene.

Travel speed

the initial speed of the viewer.

Miscellaneous Options

Export normals

output normals.

Color per vertex

ON -calculate color for each vertex.

OFF -calculate color for each polygon.

Long Lines

ON - save the VRML text file with long lines.

OFF - break the VRML text file into short lines (each value on a separate line).

Turn this option off if you want to edit the output file with a text editor that does not handle lines longer than 80 characters well (such as vi). Note that turning Long Lines off will increase the size of the output file.

Auto launch viewer

Open the new VRML file in Netscape Navigator after export.

To view VRML files in Netscape Navigator, you must have the Navigator VRML plug-in installed.

Sample Textures

Convert procedural textures to image files.

Textures

Embedded -include texture image data in the .wrl file (not currently supported).

SGI image file - convert texture images to SGI format and reference.

Use texture path in URL

Include texture path in the URL of the .wrl file.

Texture path

Same textures to this directory.

Output Section

Scene name

base name for the scene, to which the translator will add the suffix .wrl.

Output

The translator creates a file (<scene>.wrl) containing VRML code describing the scene.

Setting VRML Properties in Alias

VRML Plug-ins

The VRML plug-ins let you attach tags to objects that has no effect in Alias (sometimes called "blind data"), but will be converted to VRML code.

To add VRML properties to objects while modelling in Alias, first load the VRML plug-ins:

1. Choose Plug-in Manager from the Utilities menu.
2. Click the "load" check box next to the VRML plug-ins (VRML2Billboard, VRML2Collision, VRML2Coord, VRML2Link, and VRML2Primitive).
3. Click the Object EditVRML tools icon on the tool palette to open the VRML palette:

• The windows associated with these plug-ins are "continuous". You can continue to pick objects and the windows will reflect the picked objects' settings.
• After you set options in a plug-in window, click Go to confirm the changes. In the Link window, press the Enter key to confirm changes to the text boxes.

Linking Objects to Web Addresses with VRML2Link

1. Choose LinkVRML from the Object EditVRML tools in the Tool palette or click this icon:

   

   The system prompts:

   Select object or enter URL:
   

2. Click on the object (or objects) you want to link.

   You can select several objects before using the tool. When you enter a URL, it will be linked to all the selected objects.

3. Enter a Universal Resource Locator (URL). For example,

   http://www.aw.sgi.com
   

   You can also add a description of the destination using the form

   URL*DESCRIPTION
   

   where URL is the destination, the * (asterisk) is a separator, and DESCRIPTION is a description that will be displayed in the VRML browser when the user points at the link. For example:

   http://www.aw.sgi.com*Alias|Wavefront Web Page
   

4. When you output the scene using File Export VRML, the objects will become active VRML links.

   Notes:

• To verify a link, choose LinkVRML and then pick the object. If the object is a link, the link information appears in the command line.
• To remove a link, choose LinkVRML and then pick the object. Type - (hyphen) in the command line to remove the link information.

Creating preset VRML Viewpoints

Viewpoints are predefined camera positions and views in a VRML world. Viewpoints help viewers navigate your VRML worlds (for example, allowing them to return to an entrance point, or view close-ups of objects).

To create VRML viewpoints, do the following:

1. Create a new camera by choosing New camera from the Layouts menu.
2. Open the Camera Editor (Windows Edit Camera editor). Give the camera a meaningful name, such as EntranceView.

   

3. Select Object Edit VRML tools LinkVRML. Pick an object that will trigger the change of viewpoint. The system prompts:

   Select object or enter URL:
   

4. Type the name of the viewpoint this object will trigger, preceded by #. For example:

   #EntranceView