[x3d-public] Write Up of [was:] Euler rotation

[Leonard Daly]

On 1/6/2019 7:23 PM, John Carlson wrote:
>
> Can this be written up and placed on popular website?
>
Dies web3d.org count as a popular website? Vince's write-up is in the 
mailing list archives at 
http://web3d.org/mailman/private/x3d-public_web3d.org/2019-January/009793.html. 
These do get cataloged by Google (and other search engines).

Or are you looking for a more user-friendly description with graphics 
and examples? If you wish to write something up, there are several 
people who can help you get it posted on web3d.org

Leonard Daly


> Thanks,
>
> john
>
> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for 
> Windows 10
>
> *From: *Joseph D Williams <mailto:joedwil at earthlink.net>
> *Sent: *Sunday, January 6, 2019 7:20 PM
> *To: *Albert Jan Wonnink <mailto:awonnink at hotmail.com>; 
> vmarchetti at kshell.com <mailto:vmarchetti at kshell.com>; X3D-Public 
> <mailto: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 <mailto:awonnink at hotmail.com>
> *Sent: *Sunday, January 6, 2019 2:25 PM
> *To: *vmarchetti at kshell.com <mailto:vmarchetti at kshell.com>; X3D-Public 
> <mailto: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
>
> 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 <mailto: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
>
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-- 
*Leonard Daly*
3D Systems & Cloud Consultant
LA ACM SIGGRAPH Past Chair
President, Daly Realism - /Creating the Future/
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