VRML plug-ins

The development of VRML 2.0 capable plug-ins is still in a early stage. Although in our modules we have tried to adhere to the VRML97 specification, this means that not all VRML 2.0 browsers really support all the VRML97 specifications. The two VRML browser plug-ins we have worked with are:

The use of VRML is restricted to the Quadrupole Mass Analyzer (QMA) and QUISTOR (Ion trap) parts of the module, where it is used in two ways:

  1. In the shockwave movie with the several ions.
    Here the VRML buttons make the browser open a new window in which a VRML file is loaded from disk. This means that all VRML 2.0 browsers (at least the two mentioned above) should be able to deal with these fine.

  2. In the shockwave movie with one ion and having all parameters interactively adjustable.
    In this version, the VRML world is created 'on the fly' by a shockwave movie that simulates the ion trajectory for the particular settings made by the user. This VRML world is written to a new window that is opened with the proper mime-type specifications. The ramifications are twofold:
    1. Internet Explorer can not handle this at all, which is why we turned off the buttons completely when people are using IE.
    2. WorldView 2.0 is not able to display these 'on the fly' generated 3D worlds.

    The solution to this problem is to use CosmoPlayer 2.1 for the 1 ion fully interactive QMA part. We have found that the version previously available, 2.1a1, worked best. Unfortunately this version has a time expiration which causes Netscape to crash. The work-around for the time expiration is to temporarily set the date of the computer back.

    In the meantime a non time restricted version of CosmoPlayer, 2.1b, has come out. Unfortunately this vesion has some other more serious bugs, which cause the animation to stop. This bug seems to be present on the windows version of 2.1 also.

The possible solutions differ somewhat for each platform:

For Mac:

Here one can choose, during a Netscape run, which plug-in should be used for VRML content. We use the WorldView 2.0 plug-in for the 3-ion case, since it shows color better and seems to run faster (once the world is built). For the 1-ion case, CosmoPlayer must be used. In this case we use the 'time-bomb' version (2.1a1) because it does the infinite loop animation; but the date on the computer must be set to a date earler than 6/30/98 before Netscape is started.

For Windows:

In Windows, users can not switch which plug-in should be used for VRML, so one has to either opt for a buggy animation with CosmoPlayer, or the impossibility of viewing the 'on the fly' worlds of the 1 ion shockwave movie.

VRML on the fly

One should be aware of a potentially very useful feature which results from the way we implemented the 'on the fly' VRML world for the 1-ion QMA simulation (i.e., the one with all QMA parameters interactively adjustable). In this case the VRML text, generated by the shockwave movie, for the ion-trajectory and potential energy surface animations can be displayed, selected, copied, pasted in a text editor, and saved as "filename.wrl" (a regular text file). This file can later be opened with a web browser and the VRML world will be displayed by the VRML plug-in. This, for one reason or another, seems only to be possible with Netscape Navigator 3.01 (not with the 4.x versions). To do this one needs to temporarily modify the QMA1.htm file (in the MS:concept:QMA folder). This modified functionality is achieved by changing the javascript line

writeembed('model/vrml')

to read

writeembed('text/plain')
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