[x3d-public] x3d-public Digest, Vol 118, Issue 16

Tue Jan 8 13:22:16 PST 2019

Hi Doug,

thank you for your answer. I am admiring the work that is being done by the current working groups and it seems almost like an impossible job to get 'global' consensus about thus many parts of a specification.

In the mean time the rate of development increases exponentially, so it will probably be more and more difficult to keep specifications like x3d up with new devices and possibilities for which these are needed.

It is an interesting era.

Regards

Albert Jan

________________________________
Van: x3d-public <x3d-public-bounces at web3d.org> namens x3d-public-request at web3d.org <x3d-public-request at web3d.org>
Verzonden: maandag 7 januari 2019 14:46
Aan: x3d-public at web3d.org
Onderwerp: x3d-public Digest, Vol 118, Issue 16

Send x3d-public mailing list submissions to
        x3d-public at web3d.org

To subscribe or unsubscribe via the World Wide Web, visit
        http://web3d.org/mailman/listinfo/x3d-public_web3d.org
or, via email, send a message with subject or body 'help' to
        x3d-public-request at web3d.org

You can reach the person managing the list at
        x3d-public-owner at web3d.org

When replying, please edit your Subject line so it is more specific
than "Re: Contents of x3d-public digest..."

Today's Topics:

   1. Re: Euler rotation (GPU Group)

----------------------------------------------------------------------

Message: 1
Date: Mon, 7 Jan 2019 06:45:14 -0700
From: GPU Group <gpugroup at gmail.com>
To: X3D-Public <x3d-public at web3d.org>
Subject: Re: [x3d-public] Euler rotation
Message-ID:
        <CAM2ogRdpwmnOVDxsWXzq-ihszCUWKcs26BWfvCa6skBJtThyNQ at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

And this is a tough crowd AJ - they rake you over the coals here. No
instant applause allowed. I've submitted a few ideas through the specs
comments and very little saw its way into specs v4. Personally I love the
euler idea - in large part because I think it would welcome more users from
different backgrounds and skill levels, trying to get started in x3d.
I suspect to get things adopted, its better to become a full member, and
sit on various 'boards' where we can nurse our pet ideas through to final
specs. I would do that process but I always seem to have my year booked.
Maybe some day.
-Doug Sanden

On Mon, Jan 7, 2019 at 4:39 AM Albert Jan Wonnink <awonnink at hotmail.com>
wrote:

> Hi Joseph,
>
> Thank you for your reply. Just to be sure: the context I meant to discuss
> is about having a convenient attribute in the declarative syntax, say
> 'euler', to set the initial orientation of the transform, so anyone can use
> either 'rotation' or 'euler'.
>
> <transform euler="20 40 10" >
>
> So I interpreted Vince's $yaw, $pitch and $roll to be just placeholders,
> for manual substitution.
>
> You are right using this with either radians or degrees would be equally
> simple.
>
> Regards,
>
> Albert Jan
>
>
>
>
>
> *From: *Joseph D Williams <joedwil at earthlink.net>
> *Sent: *Sunday, January 6, 2019 7:20 PM
> *To: *Albert Jan Wonnink <awonnink at hotmail.com>; vmarchetti at kshell.com;
> X3D-Public <x3d-public at web3d.org>
> *Subject: *Re: [x3d-public] Euler rotation
>
>
>
> Hi Albert and All,
>
> When you use euler (or Tait-Bryan) angles for a while you will find that
> you get problems.
>
> Actually there is plenty of writing about the details maybe even in the
> x3d or hanim archives and widely on the web.
>
>
>
> In addition, when you create or edit the things much then you will find it
> is actually a lot easier to use quats or axis-angle radians. In general,
> for degrees, maybe your editing system may offer as a learning tool if
> radian is really an elementary block to learning, but really, never in the
> user code due to misleading simplicity and what ?cha finally gonna tell ?em
> when the gimbals lock?
>
>
>
>    - <Transform DEF="yaw-rotation" rotation="0 0 1 $yaw">
>    - <Transform DEF="pitch-rotation" rotation="0 1 0 $pitch">
>    - <Transform DEF="roll-rotation" rotation="1 0 0 $roll">
>
>
>
> Besides the fact that a variable is not allowed there
>
> (maybe use a prototype if you need a variable?)
>
> I don't think your naming of yaw and pitch and roll is reasonable for x3d.
>
>
>
> For default transform rotation 0 0 1 0, sit on it and face +z and find +y
> is up and +x is left.
>
> then fly the thing using pitch and yaw and roll.
>
> The x3d axis-angle parameters are most likely pitch yaw roll then the
> scale,
>
> and I think the same order for quaternions, except where the 'scale' is
> placed and the special limits for values.
>
>
>
> Why not try the following:
>
>
>
> DEF Pitch OrientationInterpolator {
>
> key [ 0, 0.25 0.5, 0.75 1 ]
>
> keyValue [ 0 0 1 0, 1 0 0 1.5, 0 0 1 0, -1 0 0 1.5, 0 0 1 0 ] }
>
>
>
> DEF Yaw OrientationInterpolator { key [ 0, 0.25 0.5, 0.75 1 ]
>
> keyValue [ 0 0 1 0, 0 1 0 1.5, 0 0 1 0, 0 -1 0 1.5, 0 0 1 0 ] }
>
>
>
> DEF Roll OrientationInterpolator {
>
> key [ 0, 0.25 0.5, 0.75 1 ]
>
> keyValue [ 0 0 1 0, 0 0 1 1.5, 0 0 1 0, 0 0 1 1.5, 0 0 1 0 ] }
>
>
>
> Thanks and Best,
>
> Joe
>
>
>
> *From: *Albert Jan Wonnink <awonnink at hotmail.com>
> *Sent: *Sunday, January 6, 2019 2:25 PM
> *To: *vmarchetti at kshell.com; X3D-Public <x3d-public at web3d.org>
> *Subject: *Re: [x3d-public] Euler rotation
>
>
>
> Thanks Vince, for your reply.
>
>
>
> As long as the angles and X3D code is  generated by code one can of course
> easily calculate the individual parameters for a quaternion. But during the
> testing of our experimental Unity based browser, and preparing scenes for
> that, I found it very easy to extend the transform specification with a
> degree-based Euler attribute (Tait-Bryan would also have worked).
>
>
>
> The current system still makes it relatively difficult to manually apply
> an angle of the most used fractions of PI, doesn't it?
>
>
>
> I guess this issue must have been discussed in one of the early days of
> the X3D specification. But it seems to me a lost chance to make it more
> convenient.
>
>
>
> Regards
>
>
>
>
>
> Albert Jan Wonnink
>
>
>
>
>
> [image: cid:image002.png at 01D4A5E3.FD08F950]
>
> *Van:* vmarchetti at kshell.com <vmarchetti at kshell.com>
> *Verzonden:* zondag 6 januari 2019 22:49
> *Aan:* Albert Jan Wonnink; X3D-Public
> *Onderwerp:* Re: [x3d-public] Euler rotation
>
>
>
> There is no single node Euler angle alternative representation of a
> rotation transform defined in the current (v 3.3) X3D standard.
>
>
>
> You can get an easier to edit representation of Euler angle rotation
> (specifically the Tait-Bryan angles,
> https://en.wikipedia.org/wiki/Euler_angles#Tait%E2%80%93Bryan_angles
> <https://en.wikipedia.org/wiki/Euler_angles#Tait?Bryan_angles>, commonly
> used for vehicle oriented
>
> with respect to the horizon, by nesting 3 Transforms:
>
>
>
> <Transform DEF="yaw-rotation" rotation="0 0 1 $yaw">
>
> <Transform DEF="pitch-rotation" rotation="0 1 0 $pitch">
>
> <Transform DEF="roll-rotation" rotation="1 0 0 $roll">
>
> <!-- put vehicle model here -->
>
> <Shape>...</Shape>
>
> </Transform>
>
> </Transform>
>
> </Transform>
>
>
>
> where for $yaw, $pitch, $roll you need to substitute the numerical value
> of the rotation angle in radians.
>
>
>
>
>
> Vince Marchetti
>
>
>
> On Jan 6, 2019, at 12:53 PM, Albert Jan Wonnink <awonnink at hotmail.com>
> wrote:
>
>
>
> Is there, or should there be, an Euler alternative for the transform
> 'rotation' property? This makes direct x3d code editing much easier.
>
>
>
> Regards,
>
>
>
>
>
> Albert Jan Wonnink
>
> _______________________________________________
> x3d-public mailing list
> x3d-public at web3d.org
> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>
>
>
>
>
>
> _______________________________________________
> x3d-public mailing list
> x3d-public at web3d.org
> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20190107/f75bf3fe/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 9B68D1D68F1247D1A07F4C368D0D7215.png
Type: image/png
Size: 156 bytes
Desc: not available
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20190107/f75bf3fe/attachment.png>

------------------------------

Subject: Digest Footer

_______________________________________________
x3d-public mailing list
x3d-public at web3d.org
http://web3d.org/mailman/listinfo/x3d-public_web3d.org

------------------------------

End of x3d-public Digest, Vol 118, Issue 16
*******************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20190108/6f93f508/attachment-0001.html>