Dear devs, we recently had to re-run a large project that we initially worked in in Sep 2017. We calculated daylight factors in rooms that are rather highly obstructed. I believe the assessment back in Sep 2017 was carried with HEAD-20160926. The recent re-run was probably with HEAD-20171201.
For our daylight factor simulations, with use mkillum with -ab 3. Apparently, this wasn't quite good enough in this case due to the highly obstructed nature of the site. -ab should have been increased back then, but unfortunately wasn't. We also use an external ambient file. Either way, we are not able to replicate the Sep 2017 results with the new binaries and ambient file enabled. The new results (new binaries, with -af) are up to 40% lower than the old ones. With the old binaries without an ambient file, we get the same results that we get with the new binaries (with and without) an ambient file. In other words: with the old binaries, the results are different depending on whether the ambient file is anabled or not. In the Release Notes (https://radiance-online.org/cgi-bin/viewcvs.cgi/ray/doc/notes/ReleaseNotes?view=markup) on line 2086, I noticed this entry under 'Compatibility Change' for version 5.1, which was released 8/17/2017: "Enabled ambient cache value corral for all levels, not just final two. This may reduce errors in certain pathological scenes." This sounds like an explanation of what we are struggling with. Would someone (Greg?) be able to offer some extra info on what 'ambient cache value corral' is (I did google this, but could not find anyting that seems relevant), and also what constitutes 'pathological scenes'. Am I right in saying that the new, lower results are more accurate? Thank you so much. Cheers Axel _______________________________________________ Radiance-dev mailing list Radiance-dev@radiance-online.org https://www.radiance-online.org/mailman/listinfo/radiance-dev
