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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoPlainText>Thanks for these followups Michalis.<o:p></o:p></p><div style='mso-element:para-border-div;border-top:solid #4472C4 1.0pt;border-left:none;border-bottom:solid #4472C4 1.0pt;border-right:none;padding:10.0pt 0in 10.0pt 0in;margin-left:0in;margin-right:.6in'><p class=MsoIntenseQuote align=left style='mso-margin-top-alt:.25in;margin-right:0in;margin-bottom:.25in;margin-left:0in;text-align:left'>Also: we didn't have time to go over that on the meeting, but I wanted to point out my notes on particle emitter and X3DChildNode in "X3D agenda 3 MAR 2022: announcements, Mantis issues, NurbsSweptSurface NurbsSwungSurface, planning" . In short: X3DParticleEmitterNode should not be X3DChildNode. The current spec is already correct.<o:p></o:p></p></div><p class=MsoNormal><span style='font-size:1.0pt'><o:p> </o:p></span></p><div style='mso-element:para-border-div;border-top:solid #4472C4 1.0pt;border-left:none;border-bottom:solid #4472C4 1.0pt;border-right:none;padding:10.0pt 0in 10.0pt 0in;margin-left:0in;margin-right:.6in'><p class=MsoIntenseQuote align=left style='mso-margin-top-alt:.25in;margin-right:0in;margin-bottom:.25in;margin-left:0in;text-align:left'>3. We talked at one point about making particle system emitter an X3DChildNode. I looked at spec,<o:p></o:p></p><p class=MsoIntenseQuote align=left style='mso-margin-top-alt:.25in;margin-right:0in;margin-bottom:.25in;margin-left:0in;text-align:left'><a href="https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/particleSystems.html">https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/particleSystems.html</a><o:p></o:p></p><p class=MsoIntenseQuote align=left style='mso-margin-top-alt:.25in;margin-right:0in;margin-bottom:.25in;margin-left:0in;text-align:left'>, and this would be wrong. The current state of spec is good: X3DParticleEmitterNode is supposed to be placed within ParticleSystem.emitter field. And ParticleSystem is a X3DShapeNode (which is already X3DChildNode). So, let's not change anything here. It wouldn't be valid to allow X3DParticleEmitterNode directly inside some grouping nodes.<o:p></o:p></p></div><p class=MsoPlainText>The current specification works for particle emitter nodes, fully agreed about that. Let’s press a just little bit farther please.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>The recent motivation for making X3DParticleEmitter node inherit from X3DChildNode (rather than X3DNode) is to allow these nodes to appear as root nodes in a scene, rather than solely within a ParticleSystem node’s <span style='font-family:"Courier New"'>emitter</span> field.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><ul style='margin-top:0in' type=disc><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>Mantis 836: 04.3.2 Root nodes - Additional nodes need to be allowed as root nodes <o:p></o:p></li><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>https://www.web3d.org/member-only/mantis/view.php?id=836 <o:p></o:p></li></ul><p class=MsoPlainText><o:p> </o:p></p><ul style='margin-top:0in' type=disc><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>X3D4 Architecture, 40.3.1 <i>X3DParticleEmitterNode</i><o:p></o:p></li><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/particleSystems.html#X3DParticleEmitterNode<o:p></o:p></li></ul><p class=MsoPlainText><o:p> </o:p></p><ul style='margin-top:0in' type=disc><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>X3D4 Architecture, 4.4.2.3 Interface hierarchy<o:p></o:p></li><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/concepts.html#InterfaceHierarchy<o:p></o:p></li></ul><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>This might be useful for facilitating DEF/USE re-use of such emitters in a scene with multiple particle emitters.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>That might also be considered an obscure and perhaps unhelpful use case (since emitters are then allowed to appear in many places within a model’s scene graph. I’m OK with (= can live with) either approach.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>So, staying conservative, especially at this stage of development: does anyone have a better rationale for making the emitter nodes allowed as child nodes?<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Absent any other reasons for changing we’ll simply keep it unchanged as you’ve indicated. Thanks for consideration of this small X3D4 model design point.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>all the best, Don<o:p></o:p></p><p class=MsoPlainText>-- <o:p></o:p></p><p class=MsoPlainText><span style='font-family:"Courier New"'>Don Brutzman Naval Postgraduate School, Code USW/Br brutzman@nps.edu<o:p></o:p></span></p><p class=MsoPlainText><span style='font-family:"Courier New"'>Watkins 270, MOVES Institute, Monterey CA 93943-5000 USA +1.831.656.2149<o:p></o:p></span></p><p class=MsoPlainText><span style='font-family:"Courier New"'>X3D graphics, virtual worlds, Navy robotics https://faculty.nps.edu/brutzman<o:p></o:p></span></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<br>From: Michalis Kamburelis <michalis.kambi@gmail.com> <br>Sent: Friday, March 4, 2022 5:09 PM<br>To: GPU Group <gpugroup@gmail.com><br>Cc: Brutzman, Donald (Don) (CIV) <brutzman@nps.edu>; X3D Public Mailing List (x3d-public@web3d.org) <x3d-public@web3d.org><br>Subject: Re: [x3d-public] X3D minutes 3 MAR 2022: announcements, SpotLight default values, NurbsSweptSurface NurbsSwungSurface found in FreeWrl, planning X3DOM WebXR</p><p class=MsoPlainText>Thank you all for the good meeting!<o:p></o:p></p><p class=MsoPlainText>[…].<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Also: we didn't have time to go over that on the meeting, but I wanted to point out my notes on particle emitter and X3DChildNode in "X3D agenda 3 MAR 2022: announcements, Mantis issues, NurbsSweptSurface NurbsSwungSurface, planning" . In short: X3DParticleEmitterNode should not be X3DChildNode. The current spec is already correct.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Regards,<o:p></o:p></p><p class=MsoPlainText>Michalis<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p></div></body></html>