[X3D-Public] The Network Sensor is not enough

Don Brutzman brutzman at nps.edu
Mon Feb 7 09:46:57 PST 2011

thanks for your efforts Christoph.  yes i agree that there are some
excellent ideas.

there is past work preserved at

this work got fairly far but had to stop.  quoting:
"Work on these nodes has been discontinued, at least temporarily. Because the NetworkSensor node allows definition of new fields by name, a proper implementation requires native X3D-player support and a full Prototype-based implementation is not possible. No X3D browser companies have yet committed to produce such an implementation."

if there is sufficient interest to review past work and discuss
potential future work, it would be great to schedule a teleconference.

I think that there is a lot of great work on networking that can
be capitalized on.  Deep Matrix, RayGun, BitManagement multi-user
server, proposal for Anchor/Inline url refresh, etc.

meanwhile NPS continues to offer our open-source DIS library to
integrate in other browsers, available in C++ C# Objective-C and Java.
already integrated in Xj3D.  numerous additional information about DIS
available at


plus proposed additions for X3D v3.3 on member wiki, excerpt follows


> Distributed Interactive Simulation (DIS) Component
> Latitude and longitude need to be added to the position-dependent nodes in the X3D DIS Component in a manner consistent with the X3D Geospatial Component.
> The packets defined in the IEEE DIS Specification do support high-resolution geospatial coordinates.
> Thus the following fields need to be added to EspduTransform, ReceiverPdu, SignalPdu and TransmitterPdu:
>       SFVec3d  [in,out] geoCoords      0 0 0       (-∞,∞)
>       MFString []       geoSystem      ["GD","WE"] [see 25.2.3]
> Existing translation fields in the DIS nodes are still be retained and relevant as before. Thus translation values simply reposition grouped children nodes within the geospatial coordinate frame, rather than a local coordinate frame.

url refresh is also on the member wiki:

> X3DUrlObject abstract interface: refresh for scene reload
> A major factor for improving the interactivity of X3D scenes might be to allow the deliberate reloading or refreshing of external content. This would facilitate a great deal of client-server functionality without requiring some kind of networking protocol.
> Similar functionality is provided by the http-refresh capability of HTML, for example <meta http-equiv="refresh" content="5" />. However there are some related problems with user accessibility that might be relevant.
>     9.3.2 X3DUrlObject
>     X3DUrlObject {
>       MFString [in,out] url [] [URI]
>       SFBool   [in,out] load TRUE
>       SFTime   [in,out] refresh -1
>     }
>     The refresh field specifies a refresh interval in seconds.  At each refresh interval,
>     the current url resource gets shutdown (if appropriate) and then reloaded.  A
>     refresh value of 0 or less means that no reload occurs.  If the prior reload is incomplete,
>     it is interrupted and superceded by the new refresh request.  Cached content is no longer
>     used, unless none of the refreshed content url values remain retrievable.  Time-dependent
>     media (such as AudioClip or MovieTexture) are handled as if they are again initially reloaded.


the more we do, the more we will do.  looking forward to future progress.

all the best, Don
Don Brutzman  Naval Postgraduate School, Code USW/Br      brutzman at nps.edu
Watkins 270   MOVES Institute, Monterey CA 93943-5000 USA  +1.831.656.2149
X3D, virtual worlds, underwater robots     http://faculty.nps.edu/brutzman

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