[Korea-chapter] [X3D] Korea Chapter Meeting, Apr. 6, 5:10pm PDT (Apr. 7, 9:10pm, Korea)

Don Brutzman brutzman at nps.edu
Wed Apr 6 19:22:48 PDT 2011

Attendees:  Myeong-Won Lee, Dick Puk, Jerry Kim, Gun Lee, Don Brutzman.

Congratulations Gun on your successful move to New Zealand!

On 4/6/2011 12:36 AM, "Myeong Won Lee" wrote:
> The agenda items are as follows:

Thank you for the thorough agenda.  Leonard, Dick and I reviewed it
and prepared for it during our regular X3D working group meeting this
morning.  It was very helpful to review this agenda in advance.

> 1. Administrative request for Web3D proposals
> We need a formal proposal number issued by the Web3D Consortium for each proposal
> submitted or presented at Web3D meetings.
> When submitting our annual activity reports to our sponsor, a proposal number will allow them to know that our proposals have been formally recognized by the Web3D Consortium.

This is a sensible request.  Thank you for asking.

As discussed today, we will use the list of 11 submissions that are
numbered and named in agenda item #6 below.

Let's work together to
- establish the member-only and public wiki website locations where
	they can be located
- expose the list of documents on both member-only and public wikis,
	but all links only be included on the member-only wiki.

Once complete, Leonard and I (X3D working group co-chairs) will maintain
these two copies of the submission list on the Web3D wikis for easy
reference.  That will confirm official acceptance of the proposal
submissions Web3D Consortium for further work.  We will also be happy
to maintain status of each proposal on the members-only wiki.

> 2. Korea Chapter Wiki
> We would like to divide the Korea Chapter Wiki into two: one for the Public and one for Members Only.
> For the time being, we would like to put meeting announcements and programs in the Public Wiki only; and proposal details and presentation materials in the Members Only Wiki.
> Is this possible?

Yes we can split the wikis, starting today during this meeting.

Here are the new addresses:



> 3. New work items proposals update
> 1) Units specification (Myeong Won Lee)

Please review the draft specification prose for the Units work.
Comments are welcome.

http://www.igraphics.com/Standards/ISO_IEC_19775_1_2008_WD3_Am1/Part01/components/core.html UNIT statement

Examples are available at
We need to add some other examples besides length changes.

Open work for me:  create official v3.3 DTD, create official v3.3 schema,
and add/integrate Myeong Won Lee definitions for Unit nodes.

We are wondering what is the availability of browser implementations.
Myeong Won Lee has implemented Unit browser, available for Windows,
that supports scaling changes only.  There is also an H-Anim player for
Android, which is a separate codebase, which will someday get a second
implementation.  These are private implementations and not open source,
questions can be sent to Myeong Won Lee.

It would be good to get another major browser (Xj3D, FreeWrl,
InstantReality, BS Contact, etc.)  These are listed at

> 2) Projective texture mapping (Kwan-Hee Yoo)
> 3) Mixed reality visualization (Gun Lee)

I think that MR will be considered as part of the new
Augmented Reality (AR) working group.

Jerry Kim reported progress in updating the wiki, 

On Tuesday, Dr. Yvonne Jung reported that she and Sabine Webel had very
very good discussions and email with Jerry (we think) about the AR group.
They are enthusiastic about upcoming progress, and they will discuss
what the best times are for meetings.

Discussions about X3D AR go on the X3D members list or x3d-public
list as appropriate.

> 4) CAD translation to X3D (Hyokwang Lee and Soonhung Han)
> 5) H-Anim motion data definition (Myeong Won Lee)
> Concerning additional fields for the Joint Node and a new Motion node, I have posted my response to Don's comments in the Korea Chapter's last minutes to the X3D working group mailing list.
> The motion data component is summarized as follows:
> (A) Additional fields are needed for the Joint Node of H-Anim:
> Offset: Center of a joint
> ChannelsNumber: Number of channels at a joint
> Channels: Identifiers for channels
> (B) A new Motion Node is necessary to include motion captured data for generating motion of an arbitrary H-Anim character model. This H-Anim character model can be obtained after modeling by any general modelers and converting into H-anim figure formats. The Motion Node consists of the following fields:
> Frames: Number of frames for an animation sequence
> FrameTime: Sampling rate
> Transformation: Transformation values of a joint for each frame

We had an interesting discussion about Paul Aslin's note and other
email discussion items.

We will look further whether direct streaming of MOCAP data
(or streaming of filtered MOCAP data) might be a workable
alternative approach to add to H-Anim.

> 6) Mobile X3D functions (Myeong Won Lee)
> 7) Geometric medical data (Kwan Hee Yoo)
> 8) X3D Digital Textbook (Kwan Hee Yoo)
> 9) X3D GPS Interface (Myeong Won Lee)
>  >This is under discussion by the X3D Earth working group and the latest
>  >version is documented online at http://www.web3d.org/membership/login/memberwiki/index.php/X3D_v3.3_Specification_Changes#GpsSensor_node
> In addition to a GpsSensor Node, we need to define a RealLocation Node in an X3D world. The RealLocation Node should include GPS information plus real height information in real units.

Wondering why another node is really needed, when GeoTransform and GeoLocation
nodes are also available.  Perhaps they can be adapted.

It sounds like you might be thinking about the fact that GPS latitude/longitude
values are highly accurate, while vertical elevation is inaccurate (and perhaps
derived from weather-dependent barometric pressure).

So there might be a use case that we want to use only latitude/longitude
information from a GPS sensor, and let vertical elevation be treated

Nevertheless modern GPS receivers are able to triangulate vertical height
accurately using 3 or more satellites.  So in practice, such vertical
fidelity might be sufficient for most use cases.

> Another point of consideration is if it is appropriate to handle GPS as a sensor? Mobile devices may handle a sensor-like GPS. However, if we think of non-moving facilities such as buildings or CCTV devices, these have pre-located GPS information that is maintained for a given period of time. It is fixed and invariable real information in the virtual world as well as in the real world.
> Should the GpsSensor node also include fixed location GPS information, and is the node name appropriate?

I think that create example scenes (or pseudo-X3D scenes with new nodes) that
demonstrate useful design patterns for primary use cases will be the best way
to begin resolving these questions understandably.

GpsSensor is still work in progress.  Link to proposed changes:


Please note definition 8 under Functionality definition of use cases and requirements:

Elevation. Vertical height issues can be a bit tricky; older GPS receivers might not provide an estimated altitude. GPS vertical accuracy is less than surface latitude-longitude accuracy by design. Good accuracy requires multiple satellites and extra computational effort. Some GPS receivers sometimes improve vertical accuracy by using an air-pressure sensor; the absolute height is rarely accurate (since barometric pressure changes, slowly) but real-time changes in pressure can provide a rapid measure of altitude changes. Advanced GPS receivers can therefore use Kalmann or other filter techniques to accurately estimate altitude changes. Meanwhile, an author may want to deliberately ignore altitude changes completely since any error might put an object underground or up in the air. Script filtering of altitude is simple but nevertheless clumsy and error prone. Thus a boolean clampAltitude field is needed when the vertical Y component needs to be locked at 0. 

This is definitely a thought-provoking challenge.  I eagerly await
the day when we can begin to experimentally and improve this node

Jerry thinks it is important that we co-evolve these interfaces together
with the AR interfaces.  Some harmonization and consolidation may be
possible.  Further the growing popularity of e-compasses is also worth
considering as we try to refine these interfaces to stably match use cases
and author employment practices over the long term.

Because these differences and issues are not yet fully proven, and based
on discussions in the X3D Earth working group, it appears that we should
not try to rush GpsSensor to completion to meet the imminent X3D v3.3 deadlines.

> 10) A management system of security devices in 3D virtual space (Kwan-Hee Yoo)
> 11) A CCTV node for the CCTV control of virtual environment management systems (Hyun Woo Nam)
> 4. Web3D Korea Chapter meeting at SIGGRAPH 2011
> Would you please arrange the time of the Korea Chapter around the Web3D Consortium schedule, similar to what was done last year?
> Three hours allotted for the meeting is appropriate. The purpose of the meeting is to progress our standards proposals listed above

Anita Havele will be happy to help with that request.

> 5. Scheduling the next Korea Chapter meetings
> April 13, 2011 (2nd Wed) at 5:10pm PDT (Thursday at 9:10am Korea time): CAD WG

I can make it, will be calling from Washington DC

> April 20, 2011 (3rd Wed) at 5:10pm PDT (Thursday at 9:10am Korea time): AR & e-Learning WG

if we need more time for e-Learning, we can reschedule that.
it would probably be better to have that on April 27.  Myeong-Won Lee
please investigate and decide which subjects on which date will be best.

> May 4, 2011 (1st Wed) at 5:10pm PDT (Thursday at 9:10am Korea time): Korea Chapter

Thanks everyone for a productive meeting today.

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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