[Radiance-general] Radmap: to produce irradiation map

[Rob Guglielmetti]

Prasanta Bhattarai wrote:
>
> Hi all,
>
> Being a new user to Radiance, I have very limited knowledge about it. I might be completely wrong on what I am saying. If so, please correct me and give suggestions. 
>
> My aim here is to render some before and after images for analysis of 
> daylight. I want to show existing and proposed conditions (annual) 
> irradiation maps using “radmap” tool.
>

Hi Prasanta,

Welcome to the world of Radiance! The radmap tool is actually a separate 
tool from the main Radiance distribution, but the creator, Francesco 
Anselmo, is a member of this mailing list so you may get some responses 
besides mine here. But you should definitely also check out 
http://www.bozzograo.net/radiance/ for other possible leads.

> The weather file that I am using is TMY2 .epw I used following to render existing and proposed irradiation maps with “radmap” command:
> *radmap -s 8 -a 40.8 -o 73.9 -m 57  -n 1 -w WeatherTMT2.epw --no-albedo --viewfile viewfile --radfile test.rad  -x 2048 -y 2048 --keep-temporary-maps --sky-resolution 1024 --max-kWh 500 --max-MJ 150 *
> * *
>
> As a result, I get irradiation maps in which the orientation of the 
> shading looks out by about 90deg (area on north/northwest looks 
> brighter than east/southeast).
>
> - Am I using the correct weather data or parameters?
>

Your longitude is 73.9, but your standard meridian is a slightly 
non-standard 57 degrees. I'd assume "-m 75" with "-o 73.9" will give a 
better result. Looks like you just accidentally transposed the numbers 
there...

> - I would also like to use the rpict options to get better rendering, 
> but whenever I specify the --optionfile it says,
>
> o View file to be used: *viewfile*
>
> o Option file to be used: *viewfile*
>
> o Do I have to specify the rpict options on the viewfile?
>

What version of radmap are you using? I have not used option files with 
it before, but I looked at the python code for my copy of radmap (v0.1c) 
and it doesn't seem like there's any confusion between view files and 
options files. In other words, it should be reading in your option file 
correctly despite what's being printed to the command line. You might 
want to try changing options directly in the python code; you'll see the 
options towards the top of the file and Francesco has commented 
everything fairly well. Only a few of the options are in there, but it 
served me well enough. Good luck!

- Rob Guglielmetti