Imagebased makes the surface reflective

Here when I run Imagebased simulation, The result I get without using any material is this-

ANd just by adding material property to ceiling surface, and even giving value as low as 0.1 for reflectance it renders the ceiling as mirror-

Can anyone tell me why this is happening?
Also, how can I get more realistic image with shart lighting with edges like this.

Thank you. (785.4 KB)

Is there someone who knows the solution for this??

Hi @akash.changlani, if you can post the Radiance folder (with the rad files, bat files etc) that gets written out by Honeybee, I can take a look.


Hello Sarith,
Thanks for replying. Here are the files you asked for.
Thank you.

Image based_HB .rar (35.1 KB) ImgBsd_Glare_HB Legacy.rar (121.3 KB)

Is this a question for honeybee[+] or honeybee? It looks like it has been tagged incorrectly. Honeybee[+] doesn’t have a glare component.

Diffuse reflectance is specified through the first three digits after “0 0 5” in a Plastic definition.. The reason that your ceiling is acting somewhat like a mirror is because your current definition void plastic Reflective 0 0 5 0.1 0.1 0.1 0.1 0.0 is also assigning the specularity as 0.1. If you set your definition to void plastic Reflective 0 0 5 0.1 0.1 0.1 0.0 0.0 the ceiling surface will behave normally.


PS: Typical value for celing reflectance is usually between 0.8 and 0.9

I have used both here. For Imagebased I used Honeybee Plus, as I am using honeybeePlus for my point in time Illuminanace study.
But as there is no Glare analysis available yet for HB+, to examine DGP and glare I am using HB Legacy alongside HB+.
And the issue I am getting in both version.

Thanks for the reply Sarith.
Yet I am unable to get a sun image as sharp as like this.

Hi Akash, the solar altitude is likely too high and that’s why shadows aren’t being cast.
I didn’t see the sky file in the folder that you shared, but based on the file name you are currently rendering the image for 1PM on June 21st.

Assuming your glazing is facing the south direction, try a few different times, in morning or evening during winters.