Black Sky in Luminance Results

[devang]

Does anyone have any idea why I am receiving a black color at the skylight in this point-in-time luminance simulation?

Skylight.zip (1.3 MB)Skylight.gh (1.4 MB)

The 5% VLT is deliberate. Apparently, the following simulation is done with the same parameters in DIVA and the results are very different

[devang]

Is it because the sun is visible in the view?

[sarith]

Hi Devang, this is surprising because black is not even a color on the falsecolor palette. Can you post the HDR file and the radfiles generated prior to the Radiance run?

[devang]

Thanks Sarith. I attached the files.

material_unnamed.rad (1.0 KB)
unnamed_IMG_Test.HDR (256.0 KB)
unnamed_IMG_Test@fc.HDR (133.7 KB)
unnamed_IMG_Test@fc_h.HDR (436.7 KB)
unnamed_IMG_Test@fc_cl.HDR (285.6 KB)
unnamed_IMG_Test_chkFile.HDR (250.5 KB)
unnamed_IMG_Test_noText.HDR (239.7 KB)
unnamed_IMG_Test_temp.HDR (719.2 KB)
unnamed.rad (416.3 KB)

[devang]

When I change the VLT of skylight to 40% I get the following without changing any parameters

[sarith]

Can I add the .bat file and all the geometry and sky data referenced by it? This should mostly be in the Ladybug folder.

[devang]

Thanks Sarith. Here’s the link

[JocelynUrvoy]

Hi @devang

the black color is probably because of the maskThreshold. If you set it to 0 (default 0.1) you’ll see the purple pixels back in your image. I guess you probably know it already…

Now that doesn’t explain why the skylight is so dark with VLT=0.05 while it’s bright-ish compared to the scene with VLT=0.2 (I could replicate the issue on my machine).
I’ve tried replacing the glass material with a trans but that didn’t give me an answer.

Sorry !

[devang]

Thanks a lot for taking a look. Yes I did play with the maxThreshould. First time I am experiencing this.

[devang]

Glad to know that you could replicate this. So My installation is fine. One thing ruled out. Thanks!

[sarith]

I could not recreate your error. The results appear to be fine in my installation:

By the way, the culprit appears to be your HDR itself:

I tried running the init bat commands and even they appear to render fine (given the settings):

By the way, why -ab 12?

[devang]

Thanks Sarith,
What can I do to fix this HDR problem? I just tried the file on another machine. I get the same black sky.

[sarith]

This might be a version issue. I am using Radiance 5.2.91 dated 2018-06-20 (rcontrib -version on cmd). I am also running the perl version of falsecolor (the one shipped by NREL). Can you try a simple run to see if the parameters themselves are causing the error?

My rpict and falsecolor settings:

18:59:26 |mod:_radbase|func:call|msg:Trying to run: ['rpict', '-ab', '2', '-ad', '512', '-vf', 'view.vf', 'C:\\Users\\Sarith\\AppData\\Local\\Temp\\RAD_18_592h1dyfpp\\oconv_k93367ar.oct']

19:00:03 |mod:_radbase|func:call|msg:Trying to run: ['C:\\radiance\\perl\\bin\\perl.exe', 'c:\\radiance\\bin\\falsecolor.pl', '-i', 'test2.hdr']

(disregard the logging part!)

PS: If you need a compatible perl installation, try this: https://www.dropbox.com/sh/zvxry7eehsujq7o/AADJsN_qPEsV_9flL9Xr6GdUa?dl=0

[devang]

I tried the -ab and -ad settings. The problem remains. My Radiance version would be older. I will try to use the latest version now.

[devang]

Updating the Radiance version to 5.2.91bcc23df3 NREL 2018-06-20 dd not solve the problem

[sarith]

Can you post the getinfo on the new HDR file. On cmd just getinfo filepath.hdr

[devang]

This is what I got. info.txt (7.0 KB)

[sarith]

Cant figure out either… your settings are similar to mine (except the view):

This might be worth escalating to the radiance forum.

[devang]

Thanks for all your suggestions and responses Sarith. I will do that.