falsecolor and specific isocontours

Hi,

Is there any way to tell falsecolor to draw contours at specific isolevels, instead of its automatic method?

ie. If I just wanted a contour at level 16.5 and that's all...

Thanks,

Chris

Hi Chris,

No, falsecolor doesn't offer such an option. However, you can do it yourself with pcomb:

  pcomb -e 'incontr=eq(we*li(1),16.5,0.25)' \
    -e 'ro=if(incontr,0,ri(1)' \
    -e 'go=if(incontr,1,gi(1)' \
    -e 'bo=if(incontr,0,bi(1)' \
    -e 'and(a,b):if(a,b,a)' \
    -e 'eq(a,b,eps):and(a-b+eps,b-a+eps)' \
    -o input.pic > contoured.pic

This assumes you meant 16.5 lux or nits (depending on whether "input.pic" was rendered with the -i option or not). If you meant 16.5 watts/sr/m^2, then take out the "we*" in the first expression. I also used an epsilon of 0.25 about 16.5, so anything between 16.25 and 16.75 will be colored green. If you want some other range, you can adjust this. If you want a perfectly sharp line, then you'll need to use the more sophisticated pcomb script within falsecolor, which I won't reproduce here. Other options, such as placing a contour over a tone-mapped (pcond output) image are easily accommodated by altering the command above.

-Greg

···

From: Christopher Kings-Lynne <[email protected]>
Date: February 3, 2005 3:10:37 AM PST

Hi,

Is there any way to tell falsecolor to draw contours at specific isolevels, instead of its automatic method?

ie. If I just wanted a contour at level 16.5 and that's all...

Thanks,

Chris

Hi Chris,

No, falsecolor doesn't offer such an option. However, you can do it
yourself with pcomb:

  pcomb -e 'incontr=eq(we*li(1),16.5,0.25)' \
    -e 'ro=if(incontr,0,ri(1)' \
    -e 'go=if(incontr,1,gi(1)' \
    -e 'bo=if(incontr,0,bi(1)' \
    -e 'and(a,b):if(a,b,a)' \
    -e 'eq(a,b,eps):and(a-b+eps,b-a+eps)' \
    -o input.pic > contoured.pic

Hey, this is cool Greg. I figured this was possible with pcomb, but not
really having any handle on the functional language I never knew how to go
about it. I tried your tip here, putting the whole thing into a shell
script, but I get an error: "we: undefined variable". Is there something
wrong with my environment (aside from going into New York City on a
perpetually late, crowded train every day, I mean)?

P.S. There are closing parens missing from lines 2,3,and 4.

- Rob Guglielmetti
www.rumblestrip.org

Rob, it is a problem of caps, it�s WE not we

···

----- Original Message -----
From: "Rob Guglielmetti" <[email protected]>
To: "Radiance general discussion" <[email protected]>
Sent: Thursday, February 03, 2005 6:11 PM
Subject: Re: [Radiance-general] falsecolor and specific isocontours

> Hi Chris,
>
> No, falsecolor doesn't offer such an option. However, you can do it
> yourself with pcomb:
>
> pcomb -e 'incontr=eq(we*li(1),16.5,0.25)' \
> -e 'ro=if(incontr,0,ri(1)' \
> -e 'go=if(incontr,1,gi(1)' \
> -e 'bo=if(incontr,0,bi(1)' \
> -e 'and(a,b):if(a,b,a)' \
> -e 'eq(a,b,eps):and(a-b+eps,b-a+eps)' \
> -o input.pic > contoured.pic
>

Hey, this is cool Greg. I figured this was possible with pcomb, but not
really having any handle on the functional language I never knew how to go
about it. I tried your tip here, putting the whole thing into a shell
script, but I get an error: "we: undefined variable". Is there something
wrong with my environment (aside from going into New York City on a
perpetually late, crowded train every day, I mean)?

P.S. There are closing parens missing from lines 2,3,and 4.

- Rob Guglielmetti
www.rumblestrip.org

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

Rob, it is a problem of caps, it´s WE not we

Thanks Ignacio! That did the trick. Now then: where is the best place to
look for info on this functional language?

- Rob Guglielmetti
www.rumblestrip.org

Rob- here's one place...

On the Radiance site - go to Documents and hit the "File Formats" PDF link (filefmts.pdf).

kirk

···

On Feb 3, 2005, at 2:42 PM, Rob Guglielmetti wrote:

Rob, it is a problem of caps, it´s WE not we

Thanks Ignacio! That did the trick. Now then: where is the best place to
look for info on this functional language?

- Rob Guglielmetti
www.rumblestrip.org

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

Hey Rob,

I think learning the functional language is kind of a zen thing. The best way to learn is to look at some of the simpler cals to see how things are done. There are also some examples in RwR and rayinit.cal is the source of many useful things. And also in this case the man page for pcomb also has some variables that are specific to that tool (li, lo...)

-Jack

Rob Guglielmetti wrote:

···

Rob, it is a problem of caps, it�s WE not we
   
Thanks Ignacio! That did the trick. Now then: where is the best place to
look for info on this functional language?

- Rob Guglielmetti
www.rumblestrip.org

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

Hey Rob,

I think learning the functional language is kind of a zen thing. The
best way to learn is to look at some of the simpler cals to see how
things are done. There are also some examples in RwR and rayinit.cal is
the source of many useful things. And also in this case the man page for
pcomb also has some variables that are specific to that tool (li, lo...)

Thanks Jack, and thanks Kirk, that filefmts.pdf has a boatload of info
about this stuff. Carsten Bauer actually tried to beat this stuff into my
head a couple months ago, and there was a glimmer of understanding, but
then I got distracted, and now I am back to square one on this. *sigh* So
much to learn.

Jack, I presume you used pcomb to do that shading impact study that you
presented when we were in Berkeley?

- Rob Guglielmetti
www.rumblestrip.org

Hey,

I'll also say thanks to Kirk as well! I feel like a dummy, I had never seen filefmts.pdf before! Ah, so much to learn...

-Jack

Rob Guglielmetti wrote:

···

Hey Rob,

I think learning the functional language is kind of a zen thing. The
best way to learn is to look at some of the simpler cals to see how
things are done. There are also some examples in RwR and rayinit.cal is
the source of many useful things. And also in this case the man page for
pcomb also has some variables that are specific to that tool (li, lo...)
   
Thanks Jack, and thanks Kirk, that filefmts.pdf has a boatload of info
about this stuff. Carsten Bauer actually tried to beat this stuff into my
head a couple months ago, and there was a glimmer of understanding, but
then I got distracted, and now I am back to square one on this. *sigh* So
much to learn.

Jack, I presume you used pcomb to do that shading impact study that you
presented when we were in Berkeley?

- Rob Guglielmetti
www.rumblestrip.org

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

--
# John E. de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction

Hey,

I'll also say thanks to Kirk as well! I feel like a dummy, I had never seen filefmts.pdf before! Ah, so much to learn...

-Jack

Rob Guglielmetti wrote:

···

Hey Rob,

I think learning the functional language is kind of a zen thing. The
best way to learn is to look at some of the simpler cals to see how
things are done. There are also some examples in RwR and rayinit.cal is
the source of many useful things. And also in this case the man page for
pcomb also has some variables that are specific to that tool (li, lo...)
   
Thanks Jack, and thanks Kirk, that filefmts.pdf has a boatload of info
about this stuff. Carsten Bauer actually tried to beat this stuff into my
head a couple months ago, and there was a glimmer of understanding, but
then I got distracted, and now I am back to square one on this. *sigh* So
much to learn.

Jack, I presume you used pcomb to do that shading impact study that you
presented when we were in Berkeley?

- Rob Guglielmetti
www.rumblestrip.org

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

Hey,

I'll also say thanks to Kirk as well! I feel like a dummy, I had never
seen filefmts.pdf before! Ah, so much to learn...

It has been said that everything in Radiance has been documented --
somewhere. The trick is finding it all. Or something like that. I can't
remember if it was Schorsch or Greg who said this, nor can I remember
where I read it, but I *do* remember reading it.

- Rob Guglielmetti
www.rumblestrip.org

You can say thanks to Greg - I spent some frustrating hours trying to determine the syntax of the conditional "if" -
I wasn't sure if it was some language that most unix people knew, or some specific scripting thing, or some C variant.

Turns out Greg made up a whole new functional language....I thought, "you've got to freakin' be kidding me". At least
I felt better knowing that this was a Radiance-specific thing and I was slightly less of an idiot than I normally am,
and it gave me an even deeper appreciation of Greg's effort and commitment to Radiance.

There is also a discussion of the functional Language in Rendering With Radiance - don't have the book here at work,
so I don't know the page numbers off the top of my head.

Kirk

···

On Feb 3, 2005, at 3:26 PM, Jack de Valpine wrote:

Hey,

I'll also say thanks to Kirk as well! I feel like a dummy, I had never seen filefmts.pdf before! Ah, so much to learn...

-Jack

Rob Guglielmetti wrote:

Hey Rob,

I think learning the functional language is kind of a zen thing. The
best way to learn is to look at some of the simpler cals to see how
things are done. There are also some examples in RwR and rayinit.cal is
the source of many useful things. And also in this case the man page for
pcomb also has some variables that are specific to that tool (li, lo...)

Thanks Jack, and thanks Kirk, that filefmts.pdf has a boatload of info
about this stuff. Carsten Bauer actually tried to beat this stuff into my
head a couple months ago, and there was a glimmer of understanding, but
then I got distracted, and now I am back to square one on this. *sigh* So
much to learn.

Jack, I presume you used pcomb to do that shading impact study that you
presented when we were in Berkeley?

- Rob Guglielmetti
www.rumblestrip.org

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

--
# John E. de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

Hey Kirk,

I originally used trial and error, some programming knowledge, existing cal files and the "Texturing and Modeling" text to learn how to implement procedural materials. Although, as far as I am concerned there is a huge amount still to learn!

-Jack

Kirk Thibault wrote:

···

You can say thanks to Greg - I spent some frustrating hours trying to determine the syntax of the conditional "if" -
I wasn't sure if it was some language that most unix people knew, or some specific scripting thing, or some C variant.

Turns out Greg made up a whole new functional language....I thought, "you've got to freakin' be kidding me". At least
I felt better knowing that this was a Radiance-specific thing and I was slightly less of an idiot than I normally am,
and it gave me an even deeper appreciation of Greg's effort and commitment to Radiance.

There is also a discussion of the functional Language in Rendering With Radiance - don't have the book here at work,
so I don't know the page numbers off the top of my head.

Kirk

On Feb 3, 2005, at 3:26 PM, Jack de Valpine wrote:

    Hey,

    I'll also say thanks to Kirk as well! I feel like a dummy, I had
    never seen filefmts.pdf before! Ah, so much to learn...

    -Jack

    Rob Guglielmetti wrote:

    Hey Rob,

    I think learning the functional language is kind of a zen thing. The
    best way to learn is to look at some of the simpler cals to see how
    things are done. There are also some examples in RwR and
    rayinit.cal is
    the source of many useful things. And also in this case the man
    page for
    pcomb also has some variables that are specific to that tool (li,
    lo...)

    Thanks Jack, and thanks Kirk, that filefmts.pdf has a boatload of
    info
    about this stuff. Carsten Bauer actually tried to beat this stuff
    into my
    head a couple months ago, and there was a glimmer of
    understanding, but
    then I got distracted, and now I am back to square one on this.
    *sigh* So
    much to learn.

    Jack, I presume you used pcomb to do that shading impact study
    that you
    presented when we were in Berkeley?

    - Rob Guglielmetti
    www.rumblestrip.org

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

    -- # John E. de Valpine
    # president
    #
    # visarc incorporated
    # http://www.visarc.com
    #
    # channeling technology for superior design and construction
    _______________________________________________
    Radiance-general mailing list
    [email protected]
    http://www.radiance-online.org/mailman/listinfo/radiance-general

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

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Radiance-general mailing list
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--
# John E. de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction