[x3d-public] X3D4 draft nearing readiness for ballot; Mantis 519 Event utilities, ignoring set_boolean false events

[Don Brutzman]

[cc: x3d-public]

On 11/30/2020 6:02 PM, Andreas Plesch wrote:
> Hi Don,
> 
> Thanks for considering a HTML5 annex with guidance on how X3D integration may work.

should have a draft for everyone to improve in a few days...

> I was reminded of an issue with the Event Utilities component while browsing. A while back we had a discussion that only True valued events should trigger outputs. https://www.web3d.org/x3d/content/X3dTooltips.html#IntegerTrigger <https://www.web3d.org/x3d/content/X3dTooltips.html#IntegerTrigger> mentions this as a hint for the set_boolean field with a reference to Mantis issue 519 . However, the spec. language was not updated accordingly:
> 
> https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD2/Part01/components/eventUtilities.html#IntegerTrigger <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD2/Part01/components/eventUtilities.html#IntegerTrigger>
> 
> still says "The value of set_boolean shall be ignored.", implying that False valued events also trigger output. There are similar fields for other nodes. I believe x3dom currently follows the spec., not the Tooltip.
> 
> This is not a major issue but one which may be possible to be resolved in a limited time since the necessary changes in spec. language are minimal.
> 
> all the best, -Andreas

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* Mantis 519: 30.4.6 IntegerTrigger, 30.4.7 TimeTrigger - Additional Text
   https://www.web3d.org/member-only/mantis/view.php?id=519

URL: http://www.web3d.org/files/specifications/19775-1/V3.2/Part01/components/utils.html#IntegerTrigger

Comment:
Should add sentences to each node that "The value of set_boolean shall only be honored if a TRUE value is received." This default supports simpler scene logic for most cases, matches original design intent, and avoids several TRUE/FALSE pathologies that are common to TouchSensor. Author logic that is strictly dependent on the receipt of FALSE values can be easily constructed using other event utility nodes.
============================================

You are right.  Great job remembering, this slipped under our Mantis radar... now re-elevated.

Adding this clarification streamlines event-chain logic and means authors don't have to insert a BooleanFilter any time they are routing SFBool values.

Last call for comment, if no show-stopper examples discovered then the spec revision will get added.

If someone thinks they found some kind of example, well OK but please be prepared to explain:
(a) why behavior is not ambiguous (TRUE go do something, FALSE go do something)
(b) why more direct logic isn't possible.

Have fun with X3D4!  TRUE!  8)

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 http://faculty.nps.edu/brutzman