glare evaluation

radiance-general
1

good evenign sir.

i have gone through the paper "the adaptive zone" and i ahve this
presentation also with me...which was in Radiance workshop 2010.

sir im still in confusion or i guess im misssing my basics. sorrry for this
but i need to get it cleared and hope it gets done with your help.

now here's the situation..

i have done glare simulations through Radiance and got the values thorugh
evalglare program.

for ex: these are my values for a particular renedered radiance image .

dgp - 0.299183
dgi - 23.436073

as per the index given in the presentation this is what it says.

                                            dgp dgi
imperceptible glare < 0.35 <18
percpetible glare 0.35 - 0.4 18 - 24
disturbing glare 0.4 - 0.45 24 - 31
intolerable glare > 0.45 > 31

my question is now if i go by this index :-
if i consider dgp it wil state "imperceptible glare" and
if i consider dgi it will state "perceptible"

this is my confusion and if i go by dgp then all my cases are impercpetible
glare. for which i think i m wrong somewhere ...

hope you got the situation sir. pls help me out in this and also let me know
if im wrong somewhere or missing my basics. sorry for trouble

im also hereby attaching the rendered image form radiance...

thanks
dhaRam

d9_c1.jpg640×640 33.1 KB

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---------- Forwarded message ----------
From: dharam <[email protected]>
Date: Fri, Sep 9, 2011 at 9:13 PM
Subject: glare evaluation
To: [email protected], "Reinhart, Christoph" <[email protected]>

2

Hi Dharam!

my question is now if i go by this index :-
if i consider dgp it wil state "imperceptible glare" and
if i consider dgi it will state "perceptible"

Did you read Jan's publications on the development of the DGP? It is not surprising to get different results using different methods - if the results were identical, Jan would have done the work for nothing. One of the keys is whether you have a large transmissive glazing/facade (high vertical illuminance) or more some small windows (high ratios max/min luminances). But again, it is best to read it from Jan's work, he spent some time on it. One more nice introduction by Jan is available here:

http://www.radiance-online.org/radiance-workshop8/Presentations/wienhold_rad_ws_2009_evalglare_intro.pdf

Cheers, Lars.

3

thank you sir..

il surely do....

on perosnal terms im really thankful to everyone in radiance forum who
responds so quickly and also intersting thing is ....m learning many new
more things...this will surely help me....

thank you sir

dhaRam