VRML - navigation tool examples (please)

Author

navigation tool examples (please)

John Andrews

2005-11-18, 6:31 pm

Over the years my colleagues and I have used a number of different
software products on Windows/Unix to view 3D earth-science data.
Typically, these products work in the VRML-equivalent of "EXAMINE" mode
and are, from my perspective, invariably much easier to use and more
intuitive than mine and other projects I've seen developed in VRML (and
viewed with CosmoPlayer, Contact, or Cortona). Between the 3 of these,
Cosmo is by far the easiest/most-intuitive for me. When i bring up my
data in Cosmo, the axis of rotation is stable and is generally in the
center of the object. In Contact, however, when i rotate a model a few
times, the axis-o-r changes and navigation becomes increasingly
difficult... (btw- all my vrml projects are in examine mode).
Sometimes I'll create a few viewpoints for a model: from some of these
viewpoints, the axis-of-rotation will be the center of the model, but
for other the aor is elsewhere. Again, Cosmo is much better in the
respect than either Contact or Cortona.

so, my request: ideas for and/or examples of VRML worlds in Examine
mode that employ custom (and preferably 2.0 compliant) navigation tools.

many thanks,
john

Rex Melton

2005-11-23, 6:36 pm

Hi John,

Have an example for you, though not one that you can readily access
online. It is a custom navigation scheme implemented in Java and
interfaced to the browser via the SAI. To my knowledge, the only Java
SAI capable browser is Xj3D.

Briefly....

I refer to the navigation mode as 'globe mode' since the navigation of
the model from the main user interface is much like you would experience
by spinning or tilting a globe.

The middle two controls on the toolbar in this screen shot:

http://warudo.home.comcast.net/snap..._satellites.jpg

show the main user interface. The position and orientation of the
viewpoint are separately controlled. The position is controlled by
longitude/latitude/elevation in an ellipsoidal frame of reference, or
longitude/latitude/radius in a spherical frame of reference. The
orientation is controlled by horizontal coordinates (azimuth/altitude).

There are additional modules to the system. There is functionality for
animating viewpoints, both position and orientation, along great
circles. There are modules for position and orientation animation for
tracking objects in motion (e.g. satellites, planets) - or to remain
focused on fixed positions while the viewpoint is in motion.

If any of this is of interest, contact me. Happy to share either
knowledge or code.

-Rex

John Andrews wrote:

>Over the years my colleagues and I have used a number of different
>software products on Windows/Unix to view 3D earth-science data.
>Typically, these products work in the VRML-equivalent of "EXAMINE" mode
>and are, from my perspective, invariably much easier to use and more
>intuitive than mine and other projects I've seen developed in VRML (and
>viewed with CosmoPlayer, Contact, or Cortona). Between the 3 of these,
>Cosmo is by far the easiest/most-intuitive for me. When i bring up my
>data in Cosmo, the axis of rotation is stable and is generally in the
>center of the object. In Contact, however, when i rotate a model a few
>times, the axis-o-r changes and navigation becomes increasingly
>difficult... (btw- all my vrml projects are in examine mode).
>Sometimes I'll create a few viewpoints for a model: from some of these
>viewpoints, the axis-of-rotation will be the center of the model, but
>for other the aor is elsewhere. Again, Cosmo is much better in the
>respect than either Contact or Cortona.
>
>
>so, my request: ideas for and/or examples of VRML worlds in Examine
>mode that employ custom (and preferably 2.0 compliant) navigation tools.
>
>many thanks,
>john
>
>