VRML

VRML stands for Virtual Reality Modeling Language. It can be used for defining 3D objects and scenes.

One of the best VRML viewers in my opinion is Cortona VRML Client by Parallel Graphics. They are also offering SDK, which allows incorporation of the client in other applications.

I have learned VRML with the help of Floppy's VRML guide, and I have written a module for generating VRML in EV 3D Presenter. Here is an example of generated 3D pyramid. Click on the sides of the pyramid to fold them. Click the button F on the control panel to fold the whole pyramid, U to unfold it, S to make the sides non-transparent and T to make the sides transparent. Another example shows a two-part box.
Note: the panel won't show under Microsoft VRML viewer, because Microsoft do not support correctly VRML 2.0 and their viewer can cause General Protection Fault when showing lines with emmisive color.

VRML PixelTexture Converter

I have written a simple program, which can convert a bitmap file to a VRML PixelTexture Node. It can be downloaded from the Programs page.

Cortona VRML Client 4.0 Navigation

In Cortona 4.0 the navigation in EXAMINE mode is different than in Cortona 3.x. The center of the rotation is now the center of the bounding box of the scene geometry. This may be not the desired behaviour, especially when there is a HUD (Heads Up Display), as the objects can easily rotate out of the screen.

There are two approaches to solve the problem:

Fix the scene
The VRML files can be modified to force the rotation center. An example is found on Parallel Graphics site.
The drawback of this example is that it uses Cortona-specific extension, and it may cause problems with other VRML viewers. To solve this, the following script can be used:


	    DEF NAVINFO NavigationInfo
    {
    }

    DEF SETCORTONACENTER Script
    {
      eventOut MFFloat set_avatarSize

      url "javascript:
        function initialize()
        {
          if (Browser.getName() == 'Cortona VRML Client')
          {
            set_avatarSize[3] = 0.0;
            set_avatarSize[4] = 0.0;
            set_avatarSize[5] = 0.0;
          }
        }
      "
    }

    ROUTE SETCORTONACENTER.set_avatarSize TO NAVINFO.set_avatarSize

Fix the client
The Cortona VRML Client 4.0 behaviour can be modified too, by using skins. A simple way is to modify the CAD-like skin, which comes with the instalation. It is found in
\Program Files\Common Files\ParallelGraphics\Cortona\Skins
on the Windows system drive (usualy C:\).

Open the CAD.zip archive, extract the file theme.xml and open it with a text editor. Find the line
<style id="spin" title="Spin" default="true" class="examine">
and replace the string "examine" with "examine2".
Then add the modified file back in the archive and set the Cortona Client skin to CAD-like.

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