visualize position index

Dear Radiance experts,

Learning glare related analysis, I write a .cal file to define the position
index for every point on the sky in relation to a given view vector based
on the position index formula. I also prepared a batch file to visualize it.

However, the image I got is not a circular fisheye one and the upper half
of the pattern doesn't seem to resemble what appeared on page 753 in Dr
Wienold and Dr Christoffersen's paper:
Wienold, J., & Christoffersen, J. (2006). Evaluation methods and
development of a new glare prediction model for daylight environments with
the use of CCD cameras. Energy and Buildings, 38(7), 743-757.

Images are shown here:
http://episode-hopezh.blogspot.com/2012/04/viz-position-index.html

The .cal and batch files can be downloaded from:
https://sites.google.com/site/episodehopezh/files/viz_sg.rar?attredirects=0&d=1

Two folders are included, one for visualizing the position index and the
other one for visualizing the inverted position index.

The view is a horizontal one towards due south. The image extracted from Dr
Wienold and Dr Christoffersen's paper is also included as a reference.

Can you kindly take a look of the .cal and batch file and advise me on:
1) why I can't get a circular fisheye image (I assume there's simple rookie
error in the script...)?
2) whether the position index pattern as visualized is correct?
3) how to convert the image into one using position index value as color
legend?

Would greatly appreciate if Dr Wienold can kindly provide some suggestions!

Thank you very much in advance!

- Ji

Sorry, the download link should be:
https://sites.google.com/site/episodehopezh/files/viz_pos_index_test.rar?attredirects=0&d=1

Apologize!

- JI

···

On Mon, Apr 30, 2012 at 2:15 AM, Ji Zhang <[email protected]> wrote:

Dear Radiance experts,

Learning glare related analysis, I write a .cal file to define the
position index for every point on the sky in relation to a given view
vector based on the position index formula. I also prepared a batch file to
visualize it.

However, the image I got is not a circular fisheye one and the upper half
of the pattern doesn't seem to resemble what appeared on page 753 in Dr
Wienold and Dr Christoffersen's paper:
Wienold, J., & Christoffersen, J. (2006). Evaluation methods and
development of a new glare prediction model for daylight environments with
the use of CCD cameras. Energy and Buildings, 38(7), 743-757.

Images are shown here:
http://episode-hopezh.blogspot.com/2012/04/viz-position-index.html

The .cal and batch files can be downloaded from:

https://sites.google.com/site/episodehopezh/files/viz_sg.rar?attredirects=0&d=1

Two folders are included, one for visualizing the position index and the
other one for visualizing the inverted position index.

The view is a horizontal one towards due south. The image extracted from
Dr Wienold and Dr Christoffersen's paper is also included as a reference.

Can you kindly take a look of the .cal and batch file and advise me on:
1) why I can't get a circular fisheye image (I assume there's simple
rookie error in the script...)?
2) whether the position index pattern as visualized is correct?
3) how to convert the image into one using position index value as color
legend?

Would greatly appreciate if Dr Wienold can kindly provide some suggestions!

Thank you very much in advance!

- Ji

Dear Ji,

there is an undocumented option in evalglare (-p), which replaces the luminance values to the position-index values. So you can directly generate an image just with the position index with just one command line...
You have to use evalglare in the normal manner (-> feed in image and specify output image. The content of the input image doesn't matter, just the header options must be correct.)

example: evalglare -p -c position_index.hdr inputimage.hdr

Good luck,

Jan

···

On 04/29/2012 08:15 PM, Ji Zhang wrote:

Dear Radiance experts,

Learning glare related analysis, I write a .cal file to define the
position index for every point on the sky in relation to a given view
vector based on the position index formula. I also prepared a batch
file to visualize it.

However, the image I got is not a circular fisheye one and the upper
half of the pattern doesn't seem to resemble what appeared on page 753
in Dr Wienold and Dr Christoffersen's paper:
Wienold, J., & Christoffersen, J. (2006). Evaluation methods and
development of a new glare prediction model for daylight environments
with the use of CCD cameras. Energy and Buildings, 38(7), 743-757.

Images are shown here:
http://episode-hopezh.blogspot.com/2012/04/viz-position-index.html

The .cal and batch files can be downloaded from:
https://sites.google.com/site/episodehopezh/files/viz_sg.rar?attredirects=0&d=1
<https://sites.google.com/site/episodehopezh/files/viz_sg.rar?attredirects=0&d=1>

Two folders are included, one for visualizing the position index and
the other one for visualizing the inverted position index.

The view is a horizontal one towards due south. The image extracted
from Dr Wienold and Dr Christoffersen's paper is also included as a
reference.

Can you kindly take a look of the .cal and batch file and advise me on:
1) why I can't get a circular fisheye image (I assume there's simple
rookie error in the script...)?
2) whether the position index pattern as visualized is correct?
3) how to convert the image into one using position index value as
color legend?

Would greatly appreciate if Dr Wienold can kindly provide some
suggestions!

Thank you very much in advance!

- Ji

--
Dr.-Ing. Jan Wienold
Head of Team Passive Systems and Daylighting
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

Dear Dr Wienold, Thank you very much for the advise! will try it later.

- Ji

···

On Mon, Apr 30, 2012 at 7:12 PM, Jan Wienold <[email protected]>wrote:

Dear Ji,

there is an undocumented option in evalglare (-p), which replaces the
luminance values to the position-index values. So you can directly generate
an image just with the position index with just one command line...
You have to use evalglare in the normal manner (-> feed in image and
specify output image. The content of the input image doesn't matter, just
the header options must be correct.)

example: evalglare -p -c position_index.hdr inputimage.hdr

Good luck,

Jan

On 04/29/2012 08:15 PM, Ji Zhang wrote:

Dear Radiance experts,

Learning glare related analysis, I write a .cal file to define the
position index for every point on the sky in relation to a given view
vector based on the position index formula. I also prepared a batch
file to visualize it.

However, the image I got is not a circular fisheye one and the upper
half of the pattern doesn't seem to resemble what appeared on page 753
in Dr Wienold and Dr Christoffersen's paper:
Wienold, J., & Christoffersen, J. (2006). Evaluation methods and
development of a new glare prediction model for daylight environments
with the use of CCD cameras. Energy and Buildings, 38(7), 743-757.

Images are shown here:
http://episode-hopezh.**blogspot.com/2012/04/viz-**position-index.html<http://episode-hopezh.blogspot.com/2012/04/viz-position-index.html>

The .cal and batch files can be downloaded from:
https://sites.google.com/site/episodehopezh/files/viz_sg.
rar?attredirects=0&d=1<https://sites.google.com/site/episodehopezh/files/viz_sg.rar?attredirects=0&d=1>
<https://sites.google.com/site/episodehopezh/files/viz_
sg.rar?attredirects=0&d=1<https://sites.google.com/site/episodehopezh/files/viz_sg.rar?attredirects=0&d=1>
>

Two folders are included, one for visualizing the position index and
the other one for visualizing the inverted position index.

The view is a horizontal one towards due south. The image extracted
from Dr Wienold and Dr Christoffersen's paper is also included as a
reference.

Can you kindly take a look of the .cal and batch file and advise me on:
1) why I can't get a circular fisheye image (I assume there's simple
rookie error in the script...)?
2) whether the position index pattern as visualized is correct?
3) how to convert the image into one using position index value as
color legend?

Would greatly appreciate if Dr Wienold can kindly provide some
suggestions!

Thank you very much in advance!

- Ji

--
Dr.-Ing. Jan Wienold
Head of Team Passive Systems and Daylighting
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

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