Simulations sometimes work, sometimes don't

Hi Vasken, Thanks -

My understanding from your notes is that the simulation always works but converting .hdr images to .gif or generating falsecolor image fails. I assume that it is only happening for image-based analysis?

My best guess is I messed up something when I applied parallel run for image-based analysis. I wonder if one of the pieces of the image is problematic and makes the whole process fail. Here is another case that Alexander reported recently (

Can you send me .hdr file which fails in the process of generating falsecolor image? I can look into it then. Should be an easy fix.


One more question. Did you update your Radiance recently? (e.g. did you download it from Radiance github?)

Hello Mostapha,

First, I’m running Radiance version 4.2.1.

I tried running simulations using only one core to see if it’s the multi-core part that’s problematic and that’s not the case.

What I’ve noticed is that by changing the view angle just a bit in Rhino will either make the image-based simulation work or fail. Even in “Top” view, depending on how I’ve zoomed in the scene, it makes a difference.

The falsecolor HDR seems to consistently work. The normal render HDR doesn’t always. Converting HDR to GIF is also inconsistent, and I’m not sure why since the code doesn’t change…

Here are some screenshots of a case that was successful and another that failed. I’ve also included the files. Notice the slight change in viewing angle. (3.63 MB)

The rest of the screenshots:

Thanks. Even if you only use a single CPU honeybee merges the single image with itself (I know it may not make sense but this is what happens). I will work on this during the weekend.

For the Failed picture, the component is turned orange. Did you read the warning message? I wonder if something else is wrong in the model.


I had just change the units in Rhino from mm to m and it hadn’t updated yet.

It was the “1. Default Radiance parameters are set based on meters. Make sure to modify the parameters for document units or change the units to Meters.” message.

Thanks, let me know if you want me to do anything on my side. I will continue checking out the other example files and I’ll keep you posted!

I tested out all the other files from the Honeybee examples and none are giving me any trouble! Even the file that analyses glare would render correctly.


Thanks Vasken for the update. I couldn’t get to this on the weekend but have it on the top of the list. Will get back to you soon.


Hi Vasken, I finally managed to find an hour to check this issue. It appears to be a problem with newer version of RADIANCE. I emailed Radiance community and waiting for their reply. Meanwhile if you an older version of Radiance it should work fine. Here is the installation file:

Hey Mostapha,

I downgraded Radiance to v.4.2.a and everything works flawlessly! Thank you for the support, and really, excellent work!

Have a good week,