No diffuse component in rtrace with gendaylit

Hi,

I am using rtrace to calculate the total solar radiation in a new
development in Dubai. The Radiance version is NREL version 5.0.a.3.
I am struggling because the results of rtrace do not have the diffuse
component. Points in shade have 0 W/m2 total radiation.

I generate the sky with

gendaylit 6 22 10 -W 667.0 255.0 -g 0.0 -O 1 -a 25.25 -o -55.333 -m -55 -i
60 > sky_2010062210.rad

The resulting sky is

···

-----------------------------------------------------------------------------------------------------------------------------
# /usr/local/radiance/bin/gendaylit 6 22 10 -W 667.0 255.0 -g 0.0 -O 1 -a
25.25 -o -55.333 -m -55 -i 60
# Local solar time: 10.00
# Solar altitude and azimuth: 62.6 -92.7

void light solar
0
0
3 9.814e+06 9.814e+06 9.814e+06

solar source sun
0
0
4 0.459672 0.021278 0.887834 0.533000

void brightfunc skyfunc
2 skybright perezlum.cal
0
10 5.775e+01 0.000e+00 -0.826576 -0.452548 12.755413 -3.521895 0.140043
0.459672 0.021278 0.887834
-----------------------------------------------------------------------------------------------------------------------------

The geometry is quite simple: one vertical building and a circular area of
interest at 1.5 m from the ground
(
https://dl.dropboxusercontent.com/u/1342856/Screen%20Shot%202015-06-25%20at%2016.14.39.png
)

The radiance scene also includes the ground. The circular are you see in
the picture is not exported to radiance.

This is the rtrace command I use is

rtrace -h -I -ab 2 -aa 0.15 -ar 128 -ad 512 -as 256 -ds 0.15 -dt 0.05 -w
-oov octree_2010062210.oct < mesh.pts > irradiation_2010062210.dat

The typical line in mesh.pts is something like

26.334568151370174 -2.649873307914385 1.4999999999999996 0.0 0.0 1.0

Using these commands all the points in shade appear not to have any diffuse
radiation. See image

https://dl.dropboxusercontent.com/u/1342856/Screen%20Shot%202015-06-25%20at%2016.19.16.png

I am sure I am making a fundamental mistake, but really can't understand
where the problem is.

Thanks
Ruggiero

Ruggiero,
Do you have a definition of the sky dome geometry in your scene? If not, there’s nothing emitting the brightness defined by gendaylit. Something like:

File skysources.rad or similar:

···

-------------------------------------
skyfunc glow sky_glow
0 0 4 1 1 1 0

sky_glow source sky
0 0 4 0 0 1 180

skyfunc glow ground_glow
0 0 4 1 1 1 0

ground_glow source ground
0 0 4 0 0 -1 180
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Thanks a lot Christopher,

That was actually quite a fundamental mistake!

Cheers
Ruggiero

···

On 25 June 2015 at 16:33, Christopher Rush <[email protected]> wrote:

Ruggiero,

Do you have a definition of the sky dome geometry in your scene? If not,
there’s nothing emitting the brightness defined by gendaylit. Something
like:

File skysources.rad or similar:

-------------------------------------

skyfunc glow sky_glow

0 0 4 1 1 1 0

sky_glow source sky

0 0 4 0 0 1 180

skyfunc glow ground_glow

0 0 4 1 1 1 0

ground_glow source ground

0 0 4 0 0 -1 180

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