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<br><div><div>On 4 Nov 2008, at 14:49, Pearson, Nastassja wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"> <div class="Section1"><p class="MsoNormal"><span class="Apple-style-span" style="-webkit-text-stroke-width: -1; ">I have some questions about determining/selecting material properties, specifically deciding what material type (plastic/metal) and secularity to use for the two cladding options.</span></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial"><o:p><span class="Apple-style-span" style="font-size: 12px; -webkit-text-stroke-width: -1; ">My assumptions: </span></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Marble – Originally white, but panels have become grey with dirt over time, not polished, dull finish<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Type: Plastic<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Colour: (0.91, 0.91, 0.83)</span></font></p></div></blockquote><div><br></div><div>As Randolph wrote this is far too 'white' for a typical white material,</div><div>especially if it's a bit dirty.</div><div><br></div><div>0.75 throughout would be the colour of white wallpaint, so dirty marble</div><div>might be in the range of 0.6 to 0.65 (just a guess).</div><br><blockquote type="cite"><div class="Section1"><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial"> <o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Specularity: ?????? (I think this may be low because it is not polished marble)<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Roughness: 0.05 (???)</span></font></p></div></blockquote><div>Specularity and roughness have an impact on the visual appearance</div><div>but have no effect on glare in the Radiance model.</div><div><br></div><blockquote type="cite"><div class="Section1"><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial"><o:p><span class="Apple-style-span" style="font-size: 12px; -webkit-text-stroke-width: -1; ">Glass Frit – Composed of: Clear glass, 60% coverage white frit, clear glass, 100% coverage white frit. From Window 6, I estimate the solar reflectance of the system to be around 25-35%. </span></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Typle: Metal ??? (Does the frit have specular and diffuse reflection of light?)</span></font></p></div></blockquote>Why don't you start with a glass material? If the frit is on the inside</div><div>you have at least one surface that will produce specular reflections</div><div>and might cause glare. A glass material would simulate that to some</div><div>degree. You can simulate the colour and transmittance with a trans</div><div>material behind the glass.</div><div><blockquote type="cite"><div class="Section1"><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial"><o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Colour: (1.0,1.0, 1.0)<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Specularity: ????? (Clean polished glass)<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" face="Arial"><span style="font-size:10.0pt; font-family:Arial">Roughness: 0.00</span></font></p></div></blockquote><div><br></div><div>If you are interested in glare from reflected sunlight you should also</div><div>consider a 'mirror' material to trace the sun position more accurately.</div><div><br></div><div><br></div></div>Regards,<div>Thomas</div></body></html>