materials and texfunc

radiance-general
1

Hi all:

I have some questions.

(1) Besides measure, through which methods I can find the common values of
material property, such as RBG, reflectivity and roughness value? I know
two places: Colar picker at http://luxal.eu/resources/radiance/index.shtml
and Ecotect which provides some examples, but RBG values are not 0-1, should
I divide the RBG value by 255?

(2) When typing "man texfunc", I can not find the command. Is that my
installation problem? I use ubuntu and Radiance version 4.0.

(3) Is that right I can add texture and pattern by using procedural
functions (e.g. wrinkle.cal) and bitmaps accoring to
http://www.artifice.com/radiance/rad_materials.html ? If I have an image
with an .png extension, how can I add the image as the the pattern ?

Thank you.

Jia

2

Hi Jia,

Some quick answers:

1. The Luxal resource is an excellent starting point for values, but yes measurement of your own samples is the best way. The macbethcal procedure that is documented in Rendering with Radiance is very useful, too. If Ecotect is giving RGB values in the 0-255 range, then yes you would divide the color channels by 255 to get a 0-1 value that Radiance expects.

2. textfunc is a Radiance material primitive, not a program, so there is no manual page for it. Its use is documented in the Radiance reference manual and several other places. Linkage:

http://radsite.lbl.gov/radiance/refer/materials.pdf
http://radsite.lbl.gov/radiance/refer/refman.pdf

3. To use a .png as a pattern, you need to save it in .hdr format for Radiance to use it. if you first convert the .png to .tiff, you can then use ra_tiff to convert it to .hdr format thusly:

ra_tiff -r pattern_image.tif pattern_image.hdr

Axel Jacobs has some good stuff on using images as patterns in his tutorials.

Hope this helps...

- Rob

···

On Jul 6, 2010, at 8:25 PM, Jia Hu wrote:

Hi all:

I have some questions.

(1) Besides measure, through which methods I can find the common values of material property, such as RBG, reflectivity and roughness value? I know two places: Colar picker at http://luxal.eu/resources/radiance/index.shtml and Ecotect which provides some examples, but RBG values are not 0-1, should I divide the RBG value by 255?

(2) When typing "man texfunc", I can not find the command. Is that my installation problem? I use ubuntu and Radiance version 4.0.

(3) Is that right I can add texture and pattern by using procedural functions (e.g. wrinkle.cal) and bitmaps accoring to http://www.artifice.com/radiance/rad_materials.html ? If I have an image with an .png extension, how can I add the image as the the pattern ?

Thank you.

Jia
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

3

Thank you very much. I am learning the tutorial of Axel Jacobs. It is very
good.

In Ubuntu, I built materials, rad, sky.mat, sky.rad and .vf. files, when I
use oconv to compile them, I have to input the command into the terminal
window of Ubuntu to execute the command. Can I just run a script which
contains multiple commands such as oconv and rvu?

Thanks,

Jia

···

On Wed, Jul 7, 2010 at 12:46 AM, Rob Guglielmetti <[email protected]>wrote:

Hi Jia,

Some quick answers:

1. The Luxal resource is an excellent starting point for values, but yes
measurement of your own samples is the best way. The macbethcal procedure
that is documented in Rendering with Radiance is very useful, too. If
Ecotect is giving RGB values in the 0-255 range, then yes you would divide
the color channels by 255 to get a 0-1 value that Radiance expects.

2. textfunc is a Radiance material primitive, not a program, so there is no
manual page for it. Its use is documented in the Radiance reference manual
and several other places. Linkage:

http://radsite.lbl.gov/radiance/refer/materials.pdf
http://radsite.lbl.gov/radiance/refer/refman.pdf

3. To use a .png as a pattern, you need to save it in .hdr format for
Radiance to use it. if you first convert the .png to .tiff, you can then use
ra_tiff to convert it to .hdr format thusly:

ra_tiff -r pattern_image.tif pattern_image.hdr

Axel Jacobs has some good stuff on using images as patterns in his
tutorials.

Hope this helps...

- Rob

  On Jul 6, 2010, at 8:25 PM, Jia Hu wrote:

  Hi all:

I have some questions.

(1) Besides measure, through which methods I can find the common values of
material property, such as RBG, reflectivity and roughness value? I know
two places: Colar picker at http://luxal.eu/resources/radiance/index.shtml
and Ecotect which provides some examples, but RBG values are not 0-1, should
I divide the RBG value by 255?

(2) When typing "man texfunc", I can not find the command. Is that my
installation problem? I use ubuntu and Radiance version 4.0.

(3) Is that right I can add texture and pattern by using procedural
functions (e.g. wrinkle.cal) and bitmaps accoring to
http://www.artifice.com/radiance/rad_materials.html ? If I have an image
with an .png extension, how can I add the image as the the pattern ?

Thank you.

Jia
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

4

Hi,

the typical way to automize the steps required to get an image from yor scene is to write a rif-file and let rad (look at the manpage of rad) determine what has to be done. It is a bit like using make. I would recommend not to copy one of the complete and complex rif-files coming with the examples, but to start with a minimal one.

This again is very nicely doable following Axel's tutorial!

Good luck, cheers, Lars.

···

--
Dipl.-Ing. Architect Lars O. Grobe

On Jul 8, 2010, at 3:25, Jia Hu <[email protected]> wrote:

Thank you very much. I am learning the tutorial of Axel Jacobs. It is very good.

In Ubuntu, I built materials, rad, sky.mat, sky.rad and .vf. files, when I use oconv to compile them, I have to input the command into the terminal window of Ubuntu to execute the command. Can I just run a script which contains multiple commands such as oconv and rvu?

Thanks,

Jia

On Wed, Jul 7, 2010 at 12:46 AM, Rob Guglielmetti > <[email protected]> wrote:
Hi Jia,

Some quick answers:

1. The Luxal resource is an excellent starting point for values, but yes measurement of your own samples is the best way. The macbethcal procedure that is documented in Rendering with Radiance is very useful, too. If Ecotect is giving RGB values in the 0-255 range, then yes you would divide the color channels by 255 to get a 0-1 value that Radiance expects.

2. textfunc is a Radiance material primitive, not a program, so there is no manual page for it. Its use is documented in the Radiance reference manual and several other places. Linkage:

http://radsite.lbl.gov/radiance/refer/materials.pdf
http://radsite.lbl.gov/radiance/refer/refman.pdf

3. To use a .png as a pattern, you need to save it in .hdr format for Radiance to use it. if you first convert the .png to .tiff, you can then use ra_tiff to convert it to .hdr format thusly:

ra_tiff -r pattern_image.tif pattern_image.hdr

Axel Jacobs has some good stuff on using images as patterns in his tutorials.

Hope this helps...

- Rob

On Jul 6, 2010, at 8:25 PM, Jia Hu wrote:

Hi all:

I have some questions.

(1) Besides measure, through which methods I can find the common values of material property, such as RBG, reflectivity and roughness value? I know two places: Colar picker at http://luxal.eu/resources/radiance/index.shtml and Ecotect which provides some examples, but RBG values are not 0-1, should I divide the RBG value by 255?

(2) When typing "man texfunc", I can not find the command. Is that my installation problem? I use ubuntu and Radiance version 4.0.

(3) Is that right I can add texture and pattern by using procedural functions (e.g. wrinkle.cal) and bitmaps accoring to http://www.artifice.com/radiance/rad_materials.html ? If I have an image with an .png extension, how can I add the image as the the pattern ?

Thank you.

Jia
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

5

Jia,

Lars beat me to it; rad is the tool to use, and it also can be redirected to
rvu with the "-o x11" option. You can, of course also do what you proposed,
and create a batch file or shell script to manage all the steps. The nice
thing about rad is it intelligently manages your scene files and also makes
smart choices about rendering parameters depending on what you are trying to
do. It's definitely useful to see how the various options all work
together...

- Rob

···

On 7/8/10 1:28 AM, "Lars O. Grobe" <[email protected]> wrote:

Hi,

the typical way to automize the steps required to get an image from yor scene
is to write a rif-file and let rad (look at the manpage of rad) determine what
has to be done. It is a bit like using make. I would recommend not to copy one
of the complete and complex rif-files coming with the examples, but to start
with a minimal one.

This again is very nicely doable following Axel's tutorial!

Good luck, cheers, Lars.

--
Dipl.-Ing. Architect Lars O. Grobe

On Jul 8, 2010, at 3:25, Jia Hu <[email protected]> wrote:

Thank you very much. I am learning the tutorial of Axel Jacobs. It is very
good.

In Ubuntu, I built materials, rad, sky.mat, sky.rad and .vf. files, when I
use oconv to compile them, I have to input the command into the terminal
window of Ubuntu to execute the command. Can I just run a script which
contains multiple commands such as oconv and rvu?

Thanks,

Jia

6

I will try that. Thank you. In my case, I have a number of files that need
simulation. for example, different material property, different angles of
blinds. I heart to use shell script to automatize the simulation, e.g.,
selecting the different input files by using loop.

Cheers.
Jia

···

On Thu, Jul 8, 2010 at 11:14 AM, Guglielmetti, Robert < [email protected]> wrote:

Jia,

Lars beat me to it; rad is the tool to use, and it also can be redirected
to
rvu with the "-o x11" option. You can, of course also do what you
proposed,
and create a batch file or shell script to manage all the steps. The nice
thing about rad is it intelligently manages your scene files and also makes
smart choices about rendering parameters depending on what you are trying
to
do. It's definitely useful to see how the various options all work
together...

- Rob

On 7/8/10 1:28 AM, "Lars O. Grobe" <[email protected]> wrote:

> Hi,
>
> the typical way to automize the steps required to get an image from yor
scene
> is to write a rif-file and let rad (look at the manpage of rad) determine
what
> has to be done. It is a bit like using make. I would recommend not to
copy one
> of the complete and complex rif-files coming with the examples, but to
start
> with a minimal one.
>
> This again is very nicely doable following Axel's tutorial!
>
> Good luck, cheers, Lars.
>
> --
> Dipl.-Ing. Architect Lars O. Grobe
>
> On Jul 8, 2010, at 3:25, Jia Hu <[email protected]> wrote:
>
>> Thank you very much. I am learning the tutorial of Axel Jacobs. It is
very
>> good.
>>
>> In Ubuntu, I built materials, rad, sky.mat, sky.rad and .vf. files,
when I
>> use oconv to compile them, I have to input the command into the terminal
>> window of Ubuntu to execute the command. Can I just run a script which
>> contains multiple commands such as oconv and rvu?
>>
>> Thanks,
>>
>> Jia

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Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

7

You can even call rad from within a script.

Define only the common settings for rad within the rif file, and those that change after each rad command within the script (scene=___ PICTURE=___ ). Check the rad manual page for usage syntax.

A few of rad's variables assign naming of output files, including PICTURE, OCTREE, RAWFILE, and AMBFILE (others?). Be sure to assign these names differently for each option in the script, otherwise your output images will default to common rif file name, or you could accidentally share an ambient file between options.

···

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