How to run radiance analysis only for facade reflection

radiance
#1

Hi, everyone,

I am trying to analyze a concave facade to see if there’s too much reflection on one spot. When I was doing research I found one paper mentioned there’s some radiance simulation method to run rtrace for forward ray racing and Rtcontrib to quantify the reflected daylight. Since ladybug and honeybee are open source I feel like I can modify the code to run those analysis but couldn’t locate the exact line of code to do the modification. Anyone can help?

I have got the target area that might receive too much light by run analysis of bounce of surface tool. What am I trying to do now is only cast light to the facade and to see the increase on the target area. (I have tried to run normal solar radiation and illuminance simulation with and without facade, the difference is not obvious.)

Here’s the paper I’ve read:
http://www.ibpsa.org/proceedings/BS2013/p_1232.pdf

Thanks for your help!
Qinheng

#2

I’m not sure if you need rcontrib in this case. rtrace also show the difference.

Make sure the radiance parameters are appropriate for your study and then run the analysis for before and after and use pcomb to generate a new image for the difference between the two.

pcomb w_bldgs.hdr -s -1 wo_bldgs.hdr > diff.hdr

#3

Hi @Qinheng,

Did you solve how to run the analysis for quantifying the reflected daylight from a facade?. I would appreciate some help with this topic.
I also went through the paper of the 2013 IBPSA conference and started with @mostapha’s Ray Tracing example on Hydra, but still don’t know how to display the distribution of the reflected light on the surrounding buildings.

Thanks!