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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=MsoNormal>Thanks for noting this problem Dick.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Michalis, can you please confirm that these equations are expressed correctly:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><ul style='margin-top:0in' type=disc><li class=MsoListParagraph style='margin-left:0in;mso-list:l0 level1 lfo1'>X3D4 Architecture, 12 Shape component, 12.4.6 PhysicalMaterial<o:p></o:p></li><li class=MsoListParagraph style='margin-left:0in;mso-list:l0 level1 lfo1'>https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/shape.html#PhysicalMaterial <o:p></o:p></li><li class=MsoListParagraph style='margin-left:0in;mso-list:l0 level1 lfo1'>(then scroll down, copy follows)<o:p></o:p></li></ul><div style='mso-element:para-border-div;border:none;border-bottom:solid windowtext 1.5pt;padding:0in 0in 1.0pt 0in'><p class=MsoNormal style='border:none;padding:0in'><o:p> </o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The following equations show how to calculate bidirectional reflectance distribution function (BRDF) inputs (<i>c<sub>diff</sub></i>, <i>F<sub>0</sub></i>, <i>"á </i>) from the metallic-roughness material properties.<o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>const dielectricSpecular = rgb(0.04, 0.04, 0.04)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>const black = rgb(0, 0, 0)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>c<sub>diff</sub> = lerp(baseParameter * (1 - dielectricSpecular.r), black, metallicParameter)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>F<sub>0</sub> = lerp(dieletricSpecular, baseParameter, metallicParameter)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New";background:yellow;mso-highlight:yellow'>á = roughnessParameter ^ 2</span><span style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p><div style='mso-element:para-border-div;border:none;border-bottom:solid windowtext 1.5pt;padding:0in 0in 1.0pt 0in'><p class=MsoNormal style='border:none;padding:0in'><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p></div></div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>all the best, Don<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>-- <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Don Brutzman Naval Postgraduate School, Code USW/Br brutzman@nps.edu<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;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=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>X3D graphics, virtual worlds, Navy robotics https://</span> <span style='font-size:10.0pt;font-family:"Courier New"'>faculty.nps.edu/brutzman<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> Richard Puk <puk@igraphics.com> <br><b>Sent:</b> Friday, May 27, 2022 8:46 AM<br><b>To:</b> Brutzman, Donald (Don) (CIV) <brutzman@nps.edu><br><b>Subject:</b> Bad Equation in 4.0 clean version<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div style='border:solid #004679 1.0pt;padding:2.0pt 2.0pt 2.0pt 2.0pt'><p class=MsoNormal style='line-height:12.0pt;background:#004679'><span style='font-size:10.0pt;color:yellow'>NPS WARNING: *external sender* verify before acting.<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-size:12.0pt'>Hi, Don –<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>This is the requested e-mail listing the bad equation at the end of 12.4.6 PhysicalMaterial.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal>/******************************************<o:p></o:p></p><p class=MsoNormal>| Richard F. Puk, Ph.D., President<o:p></o:p></p><p class=MsoNormal>| Intelligraphics Incorporated<o:p></o:p></p><p class=MsoNormal>| 7644 Cortina Court<o:p></o:p></p><p class=MsoNormal>| Carlsbad, CA 92009-8206<o:p></o:p></p><p class=MsoNormal>| Tel: +1-760-753-9027 Mobile: +1-760-809-9027<o:p></o:p></p><p class=MsoNormal>| Email: <a href="mailto:puk@igraphics.com">puk@igraphics.com</a><o:p></o:p></p><p class=MsoNormal>\****************************************** <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>