[x3d-public] Wishlist for view3dscene

[Joseph D Williams]

"""
Hey, my stuff no longer works! My models (in glTF, X3D, whatever) have
vertexes at coordinates like Z = 0.00001, 0.00002, 0.00003. And now,
after processing and saving to X3D using your tools, they are all
equal zero, resulting in bugs (things start to fight in Z buffer).
"""

Not surprizing because there is nothing in Hanim that requires that precision.
These are all zero. Show example. 



From: Michalis Kamburelis
Sent: Friday, February 10, 2023 5:13 AM
To: Brutzman, Donald (Don) (CIV)
Cc: Joseph D Williams; X3D Public Mailing List (x3d-public at web3d.org)
Subject: Re: Wishlist for view3dscene

Thanks, and sorry for a delay in answering!

The "description" field has been added to texture nodes and few more,
as you can see in another thread on x3d-public :)

As for digits precision when saving: it's not so easy, in general it's
(one of) the problems that come from X3D using text representation for
floats in per-vertex data. Namely, if we cut the saved numbers to 4
decimal places, I'm 90% sure that I will get a valid bugreport from
someone:

"""
Hey, my stuff no longer works! My models (in glTF, X3D, whatever) have
vertexes at coordinates like Z = 0.00001, 0.00002, 0.00003. And now,
after processing and saving to X3D using your tools, they are all
equal zero, resulting in bugs (things start to fight in Z buffer).
"""

Surely we could add a configuration option for it, but it feels
counter-productive, when my recommendation to everyone would be still
"use the maximum precision, to be safe". I would add a feature that I
explicitly say should not be used.

In the end, the longer text representation for numbers only hurts the
file size. And I don't believe we can really fix it by outputting less
digits. The right solution is storing per-vertex data in a binary
blob, when each float is binary 4 bytes, so it's

- efficient storage
- efficient reading by X3D implementation to a "float[] array", no
need for text parsing.

Regards,
Michalis




śr., 28 gru 2022 o 21:00 Brutzman, Donald (Don) (CIV)
<brutzman at nps.edu> napisał(a):
>
> Hi Michalis. Joe and I are really enjoying the many excellent features of view3dscene.
>
>
>
> Here are some suggested refinements and improvements.
>
>
>
> View3dscene converter: round off significant digits, rather than 10+ decimal places.  (For example, suggested values in HAnim spec go to 4 decimal places.
>
>
>
> View3dscene: note that we have added ‘description’ field to many nodes in X3D4, including ImageTexture.
>
> 1 warnings:
> X3D: Unknown X3D field name (unhandled X3D XML attribute) "description" in node "ImageTexture"
> Scene URL: "C:\x3d-code\www.web3d.org\x3d\content\examples\HumanoidAnimation\Skin\JoeSkeletonSkinSiteSaluteWalk.x3d".
> Use "File->View Warnings" menu to view these warnings again.
>
>
>
> Coming soon: import test of three models in HAnim Motion specification.
>
> https://www.web3d.org/documents/specifications/19774/V2.0/MotionDataAnimation/MotionDataAnimation.html
>
>
>
> Again thanks for great work.
>
>
>
> 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 graphics, virtual worlds, Navy robotics https:// faculty.nps.edu/brutzman
>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20230211/e78d2f72/attachment.html>