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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>What are the dimensions and resolution of your grid in 11.pts
compared to the full boundary of your scene (including ground plane and anything
else) in 11.oct? Maybe –ar is not high enough.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>What is your sky definition going into 11.oct?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'>Do you have an rcalc command to convert the output in 11.dat?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
radiance-general-bounces@radiance-online.org
[mailto:radiance-general-bounces@radiance-online.org] <b>On Behalf Of </b>Victor
Li<br>
<b>Sent:</b> Thursday, December 10, 2009 8:34 PM<br>
<b>To:</b> Radiance general discussion<br>
<b>Subject:</b> Re: [Radiance-general] Daylight factor<o:p></o:p></span></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><span style='color:black'>The </span><span
style='font-size:10.0pt;color:black'>rtrace setting is "rtrace -I -h -dp
2048 -ar 32 -ms 0.063 -ds .2 -dt .05 -dc .75 -dr 3 -sj 1 -st .01 -ab 8 -aa .1
-ad 512 -as 256 -av 0.01 0.01 0.01 -lr 12 -lw .0005 -af 11.amb 11.oct
< 11.pts > 11.dat</span>" And the two calculations of daylight
factor and illuminance are all the same settings. What do you think?<o:p></o:p></p>
<div>
<p class=MsoNormal>2009/12/10 Christopher Rush <<a
href="mailto:Christopher.Rush@arup.com">Christopher.Rush@arup.com</a>><o:p></o:p></p>
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<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='font-size:10.0pt;color:#1F497D'>It would help to know your command
process for calculating illuminance and daylight factor to troubleshoot.</span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='font-size:10.0pt;color:#1F497D'>Also, if your rpict/rtrace ambient
sampling settings are not stringent enough, differences could be due to random
sampling variation between two different calculation runs.</span><o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p>
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<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span
style='font-size:10.0pt'>From:</span></b><span style='font-size:10.0pt'> <a
href="mailto:radiance-general-bounces@radiance-online.org" target="_blank">radiance-general-bounces@radiance-online.org</a>
[mailto:<a href="mailto:radiance-general-bounces@radiance-online.org"
target="_blank">radiance-general-bounces@radiance-online.org</a>] <b>On Behalf
Of </b>Victor Li<br>
<b>Sent:</b> Thursday, December 10, 2009 4:04 AM<br>
<b>To:</b> Radiance general discussion<br>
<b>Subject:</b> [Radiance-general] Daylight factor</span><o:p></o:p></p>
</div>
<div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Dear:<br>
<br>
Daylight factors are expressed as the percentage of natural light falling on a
work surface compared to that which would have fallen on a completely
unobstructed horizontal surface under exactly the same sky conditions. Thus, a
daylight factor of 5% on an internal surface means that it received only 1/20th
of the maximum available natural light.<br>
<br>
so we can calculate daylight factor by RADIANCE with a overcast sky. Then i
calculated the illuminance under overcast sky. I found the distribution of
illuminance and skyfactor in the room is different. For example, in the room
ratio of minimum to average of daylight and illuminance are quite different.
Would you tell me the reason?<br>
<br>
Best Regards!<o:p></o:p></p>
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<pre>____________________________________________________________<o:p></o:p></pre><pre>Electronic mail messages entering and leaving Arup business<o:p></o:p></pre><pre>systems are scanned for acceptability of content and viruses<o:p></o:p></pre></div>
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