[x3d-public] X3D minutes 11 FEB 2022: , X3D4 Particle Systems component review, adding enabled field to X3DParticleEmitterNode ?

[John Carlson]

It also might be good to enable a kind of slo-mo effect, if not already
handled.  Also an emitter going in reverse.

So maybe something that goes -1 (backwards), 0 (disabled), 1 (enabled), and
various slo-mo settings in-between.   This would be a weighted factor on
speed, where speed provides the maximum speed without the slo-mo setting.

On Fri, Feb 11, 2022 at 12:54 PM John Carlson <yottzumm at gmail.com> wrote:

> I think it would be better to offer a transition from enabled to disabled
> and back.   But perhaps that’s max speed and min speed?
>
> But I agree that enabled is a good start, and adding a field for full on
> and full off with no transition is a good idea.   One might think of scenes
> where a door is shut.
>
> I’m not sure if full on/full off matches physical reality.   I can think
> of examples like bombs, volcanoes and dropping things though.
>
> A combination of min/max speed and on/off would cover the cases I’m
> thinking of.
>
> John
>
> On Fri, Feb 11, 2022 at 12:36 PM Brutzman, Donald (Don) (CIV) <
> brutzman at nps.edu> wrote:
>
>> Tweeted:
>>
>>
>>
>>    - X3D meeting minutes 11 FEB 2022: #X3D4 Architecture Particle
>>    Systems component review.  Community question: is it OK to add 'enabled'
>>    field to all emitter nodes, providing simpler animation control by authors
>>    and end users?
>>    - https://twitter.com/Web3DConsortium/status/1492205445120815105
>>
>>
>>
>> Request: if anyone has links or screenshots of Particle System models in
>> X3D4, we are happy to share them publicly. Thanks in advance for all posts.
>>
>>
>>
>> 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
>>
>>
>>
>> *From:* Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
>> *Sent:* Friday, February 11, 2022 9:28 AM
>> *To:* X3D Public Mailing List (x3d-public at web3d.org) <
>> x3d-public at web3d.org>
>> *Cc:* Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
>> *Subject:* X3D minutes 11 FEB 2022: , X3D4 Particle Systems component
>> review, adding enabled field to X3DParticleEmitterNode ?
>>
>>
>>
>> Attendees: Anita Havele, Vince Marchetti, Dick Puk, Don Brutzman.
>> Regrets: Nicholas Polys, John Carlson.
>>
>>
>>
>>    1. Completed X3D4 Particle Systems component review.  All Mantis
>>    issues updated and resolved.  Latest modifications highlighted via CSS with
>>    corresponding Mantis issues documented using /title/ attributes.
>>
>>
>>
>>    - X3D4 Architecture, clause 37 Particle Systems component
>>    -
>>    https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/particleSystems.html
>>
>>
>>
>>
>>
>> a. Improved issue notes, WindPhysicsModel:
>>
>>
>>
>>    - Mantis 464: 40.4.10 WindPhysicsModel - Question on Speed
>>    - https://www.web3d.org/member-only/mantis/view.php?id=464
>>    - Related issue: Mantis 768.  Deferred to X3D 4.1
>>
>>
>>
>> Likely pressure equation for future use will be based on difference
>> between particle speed and wind speed.
>>
>> Note that the turbulence definition (regarding variability of wind
>> direction) also needs improvement. For example, can highly turbulent wind
>> stop or reverse direction?
>>
>>
>>
>>
>>
>> b. New deficiency noted: how do you turn off an emitter node?
>>
>>
>>
>> No /enabled/ field is present.  Possibly /speed/ might be zero, but then
>> particle geometry would still be present and perhaps pulsing...  Possibly a
>> Switch node might hide it, but then the browser writer likely just turns it
>> off anyway to save computational resources, which is functionally
>> equivalent to enabled FALSE.
>>
>>
>>
>> We discussed in some depth… Have raises an issue in Mantis, here posted
>> publicly.  We seek comment, and decide (hopefully next week) whether it is
>> something to be accomplished in X3D 4.0 or else deferred to X3D 4.1.
>>
>>
>>
>>
>>
>>    - Mantis 1380: ability to disable/enable X3DParticleEmitterNode
>>    - https://www.web3d.org/member-only/mantis/view_all_bug_page.php
>>
>>
>> Authors are unable to easily turn particle emitter nodes on or off.
>>
>> X3DParticleEmitterNode (and implementing nodes) need field:
>>
>>    SFBool [in out] enabled TRUE
>>
>> Implementation is simple for browsers. This field has no impact on legacy
>> content.
>>
>> Current workarounds:
>> * Possibly /speed/ might be zero, but then a particle would still be
>> present and pulsing...
>> * Possibly a Switch node might hide the emitter, but then the browser
>> writer likely turns it off anyway to save computational resources, which is
>> functionally equivalent to enabled FALSE.
>>
>>
>>
>> Of related note: X3DParticlePhysicsModelNode in this component does
>> include an enabled field, for identical purposes.
>>
>>
>>
>>
>>
>> Vince discussed his Browser Review document noting X3D support, we hope
>> to look at this draft further next week.
>>
>> No member-only information included on this page.
>>
>>
>>
>> Hope everybody has another great week.  Have fun with X3D!
>>
>>
>>
>> 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
>>
>>
>> _______________________________________________
>> 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/20220211/fae591a5/attachment.html>