Hi, I got some questions about the detail level of the Radiance Parameter Component. In the same PIT Grid base simulation, different parameter results in entirely different readings. The capture shows how ridiculous this thing can be. From left to right sets defaults setting(didn’t connect anything …

You see the highest are almost the same, that is probably the area with direct sun and/of fewest bounces. The darker areas are more dependent on extra bounces and this they can differ on the -ab parameter. Also your “high” image looks like it’s totally red, but also looks like your legend max value…

After several tryings, it is the -ab that causes leaps of readings in the indirect area. Thank you Mathiassn!

Hi @Zed . You can go through this webpage from radiance that gives guidelines for setting accurate radiance parameter. “SETTING RENDERING OPTIONS” https://floyd.lbl.gov/radiance/refer/Notes/rpict_options.html

Thank you! and here are some other sources that I found during the searching, for the convenience of other guys who may have the same question as I did. JM_AmbientCalculation.pdf 7.29 MB shows the difference of different para(but in my simulation, it changed …

Hi @Zed , Welcome to the world of Radiance parameters! They can make a big difference but certain parameters and situations can make a REALLY big difference. Here’s another example with Annual Daylight, which shows that things can be really wrong if you use cruddy parameters: [image] Ambient Bou…

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Different Radiance parameter detail levels derived some ridiculous results

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