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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>I have entered these excellent comments in the Mantis issue tracker as<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 1444: Table 17.5 missing description of local variable fogVisibility; table term/title errata<o:p></o:p></li><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>https://www.web3d.org/member-only/mantis/view.php?id=1444<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'>Mantis 1445: 24.3.2 X3DFogObject, 24.4.4 LocalFog have incorrect negative signum on limit for visibilityRange<o:p></o:p></li><li class=MsoPlainText style='mso-list:l0 level1 lfo1'>https://www.web3d.org/member-only/mantis/view.php?id=1445<o:p></o:p></li></ul><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Dick and I are meeting with other ISO editors Monday. The changes are editorial, and so am hoping that these corrections can be applied now as formal editor comments pending final ISO/IEC approval of the ISO proof document. If not, they will have to be a formal corrigendum or else postponed to X3D 4.1.<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-size:9.0pt;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-size:9.0pt;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-size:9.0pt;font-family:"Courier New"'>X3D graphics, virtual worlds, navy robotics https://faculty.nps.edu/brutzman</span><o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<br>From: Michalis Kamburelis <michalis.kambi@gmail.com> <br>Sent: Wednesday, October 18, 2023 12:29 PM<br>To: Andreas Plesch <andreasplesch@gmail.com><br>Cc: Brutzman, Donald (Don) (CIV) <brutzman@nps.edu>; Holger Seelig <holger.seelig@yahoo.de>; puk@igraphics.com; X3D <x3d-public@web3d.org><br>Subject: Re: [x3d-public] visibilityRange for X3DFogObject: specification erratum detected</p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>NPS WARNING: *external sender* verify before acting.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Hi,<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>I completely agree with Andreas proposed addition to define<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>"""<o:p></o:p></p><p class=MsoPlainText>- fogVisibility (Table 17.5) is the currently bound fog's visibilityRange, in the same coordinate system as fogDistance.<o:p></o:p></p><p class=MsoPlainText>"""<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>> Michalis may have background on introducing the 'fogVisibility' term.<o:p></o:p></p><p class=MsoPlainText>> Perhaps it is an attempt to decouple from the fog node to allow <o:p></o:p></p><p class=MsoPlainText>> flexible use of world or local coordinate systems for computations.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>I'm afraid I don't have any additional insight as to why it is called "fogVisibility". It was already called like that in X3D 3.3, before my PBR edits ( <a href="https://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/lighting.html"><span style='color:windowtext;text-decoration:none'>https://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/lighting.html</span></a><o:p></o:p></p><p class=MsoPlainText>) and it was also not explicitly defined there. So I neither broke nor improved that state when editing that section for X3D 4.0 :) The theory above from Andreas sounds good -- i.e. the term is called "fogVisibility" to make it clear that it is not "just straightforward visibilityRange" value, and instead it is "visibilityRange converted<o:p></o:p></p><p class=MsoPlainText>(scaled) by the fog node transformation".<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>I believe the intention was always just like Andreas said, and it matches CGE/view3dscene implementation too.<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><p class=MsoPlainText>śr., 18 paź 2023 o 16:22 Andreas Plesch <<a href="mailto:andreasplesch@gmail.com"><span style='color:windowtext;text-decoration:none'>andreasplesch@gmail.com</span></a>> napisał(a):<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> Hi Don,<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> Thanks.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> > Andreas, if you have suggested prose for “explain that fogVisibility corresponds to the visibilityRange field” then please send that. We can at least create a Mantis issue for eventual resolution.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> The table 17.5 at<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> <a href="https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.pr"><span style='color:windowtext;text-decoration:none'>https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.pr</span></a><o:p></o:p></p><p class=MsoPlainText>> oof/Part01/components/lighting.html#t-foginterpolant<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> mentions 'fogVisibility' but the term is not clearly defined.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> The bullet list above the table has<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> - fogInterpolant is the fog interpolant, see Table 17.5 for calculation.<o:p></o:p></p><p class=MsoPlainText>> - fogDistance is the distance from point on geometry to viewer's <o:p></o:p></p><p class=MsoPlainText>> position, in coordinate system of current fog node.<o:p></o:p></p><p class=MsoPlainText>> - fogColor is the currently bound fog's color.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> Let me suggest expanding that list with an additional line:<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> - fogVisibility (Table 17.5) is the currently bound fog's <o:p></o:p></p><p class=MsoPlainText>> visibilityRange, in the same coordinate system as fogDistance.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> Michalis may have background on introducing the 'fogVisibility' term.<o:p></o:p></p><p class=MsoPlainText>> Perhaps it is an attempt to decouple from the fog node to allow <o:p></o:p></p><p class=MsoPlainText>> flexible use of world or local coordinate systems for computations.<o:p></o:p></p><p class=MsoPlainText>><o:p> </o:p></p><p class=MsoPlainText>> Best, Andreas<o:p></o:p></p></div></body></html>