Re: Friday Flashback #262

[Jennifer Goldfinch]

That was an awesome day when we posted that.

Sent from my iPhone

> On Feb 12, 2016, at 10:25 AM, Stephen Blair  wrote:
> 
> SOFTIMAGE|XSI user story
> Capcom Lost Planet user story 
> 2006
> 
> http://wp.me/powV4-3hD

Re: Arnold (SiToA) for toon shading?

[Pierre Schiller]

I'll try that. I read that obq thing goes to c:/windows. Glad you share
some light on this. Toon shaders are my main interest along that hair
shading dll.

Thanks
On Feb 11, 2016 11:45 PM, "javier gonzalez"  wrote:

>  This dll  Obq_Shaders__Core__v304.dll goes to:
> Z:\Softimage
> Workgroup\TestWorkgroup\Addons\SItoA\Application\Plugins\bin\nt-x86-64
>
> and the spdl files goes to: Z:\Softimage
> Workgroup\TestWorkgroup\Addons\SItoA\Application\spdl
>
> hope this help.
>
> 2016-02-11 21:37 GMT-06:00, Pierre Schiller <
> activemotionpictu...@gmail.com>:
> > It shows an error for recent arnold versions. I placed all the .dlls
> inside
> > users/autodesk/softimage2014/addons/SitoA/bin/x82-64 folder, but still
> > shows error that shaders are not defined. Could anyone help me out with
> > this? Thanks.
> > On Jan 23, 2016 10:39 PM, "Pierre Schiller"
> > 
> > wrote:
> >
> >> I saw thw obq toon and I also saw how it didn't work thread. But, with
> >> all
> >> of that, has anyone worked with that arnold toon shading?
> >> On Jan 22, 2016 5:47 PM, "Francois Lord"  wrote:
> >>
> >>> Yes.
> >>> http://s3aws.obliquefx.com/public/shaders/help_files/Obq_Toon.html
> >>>
> >>> On 01/21/16 17:52, Pierre Schiller wrote:
> >>>
> >>> Hello. I was looking at Transformers Devastation videogame and I got
> >>> across this article:
> >>>
> >>>
> http://www.gameranx.com/updates/id/29176/article/transformers-devastation-director-used-special-shading-to-recreate-80s-anime-look/
> >>>
> >>> I was also looking if by any means was possible for Arnold to recreate
> >>> the shader. I know it´s a professional secret from their company, but I
> >>> haven´t recalled any works for cell shadig (toon render) from Arnold (I
> >>> know it takes advantage of physical calcs for light+materials) but how
> >>> about Toon shading?
> >>>
> >>> Thanks. :)
> >>>
> >>> --
> >>> Portfolio 2013 
> >>> Cinema & TV production
> >>> Video Reel 
> >>>
> >>>
> >>>
> >
>
>

Friday Flashback #262

[Stephen Blair]

SOFTIMAGE|XSI user story
Capcom Lost Planet user story
2006

http://wp.me/powV4-3hD

Re: Softimage and CMYK

[Sebastien Sterling]

The warning is activated. but it doesn't put up any messages.

On 12 February 2016 at 18:13, Sven Constable 
wrote:

> If the color changes when bringing it into PS, it means:
>
> A. Your settings in PS for CMYK uses a different profile than the file
> uses and warning about profile mismatch is disabled.
> B. The original file has no colorprofile and PS is set to not ask about
> missing profiles.
>
> C. There is no color shift. PS displays it correctly.
>
>
>
>
>
> *From:* softimage-boun...@listproc.autodesk.com [mailto:
> softimage-boun...@listproc.autodesk.com] *On Behalf Of *Sebastien Sterling
> *Sent:* Friday, February 12, 2016 5:39 PM
> *To:* softimage@listproc.autodesk.com
> *Subject:* Re: Softimage and CMYK
>
>
>
> The problem here is that the cmyk image already has a decoloration when I
> bring the .PDF into photoshop no matter what profiles I use there is still
> that basterding color shift.
>
> On 12 Feb 2016 15:50, "Jason S"  wrote:
>
> I found out when wanting to copy the lightness channel from the CMYK image
> converted to lab to paste it in an RGB ver, and saw that just converting
> all of it from there to RGB seemed to do the trick.
>
> Maybe because as lab works with a lightness channel, it doesnt need to do
> any specific curve manipulations to recreate levels in another space
>but go figure.
>
> nevertheless, hope that can work!
> J
>
> On 02/12/16 10:13, Jason S wrote:
>
> You can have CMYK images in 16 or 32 too, but if your sources are 8 bit,
> it can be fine if there aren't too wide gradients or making wild corrects.
>
> But here's what seems to work,
>
> converting from CMYK -> Lab Color  seems to keep all levels as they were,
> and then from Lab Color -> to RGB  ... also seems to keep all levels as
> they were!
>
> (It might be best to convert to 16bit (if they were in 8) before doing so.)
>
> Cheers,
> J
>
> On 02/12/16 10:08, Sebastien Sterling wrote:
>
> I think it has to do with RGB being additive; adding all colors leads to
> white
>
> and CMYK being subtractive. adding all colors leads to black
>
> RGB has so many more colors, it must be like clamping the bit depth but
> not quite.
>
> at any rate you loose something going one way, so it is a destructive
> workflow.
>
>
>
> On 12 February 2016 at 14:55, Jason S  wrote:
>
> It weird because if you take screenshot while in CMYK colorspace and paste
> in an RGB image,
> there you go, same blacklevels and everything as in CMYK but in RGB space.
>
> So would there be a way to "bake" color info from one colorspace to
> another?
> (assuming it's for hirez images, otherwise you could just take screenshots
> :P )
>
> I find it surprising that something like photoshop cant manage to make a
> 1:1 conversion.
>
>
> On 02/11/16 18:19, Sebastien Sterling wrote:
>
> Have been doing variants of this, to no great success, it doesn't seem to
> want to change anything, haven't tried absolute colometric though, maybe i
> will try that. The Web converter actually does have an effect, but not
> perfect, it does bring the ultramarines back towards black.
>
>
>
> On 11 February 2016 at 23:02, Sven Constable 
> wrote:
>
> Photoshop Edit->Convert To Profile
>
> You will see the source color space embedded in the original (if there is
> any) and the target color space.
>
> Choose  one of the RGB spaces (eg. sRGB).
>
> Check blackpoint compensation and Relative Colometric.
>
> Tick Preview to see the result.
>
> Ideally you should see no to minimal color shifting, but this depends on
> the original color profile within the CMYK file.
>
>
>
> I'm pretty sure this what you'll get with that web based converter.
>
> However, your problem is not to get a close color match but to change
> colors (ultramarine blue to black). Not sure if this is possible without
> manual grading but you can try *unchecking black point compensation* and
> switch to *Absolute Colometric*. Then switch through the different color
> profiles and see if any of it will change the ultramarine blue back to
> black.
>
> If this worked somehow, do a second conversion to sRGB *with blackpoint
> compensation ON and relative colometric*.
>
>
>
> If this won't work, I think there is only manual color grading or have the
> client send you "correct" files.
>
>
>
> sven
>
>
>
>
>
>
>
>
>
>
>
>
>

RE: Softimage and CMYK

[Sven Constable]

If the color changes when bringing it into PS, it means:

A. Your settings in PS for CMYK uses a different profile than the file uses and 
warning about profile mismatch is disabled.
B. The original file has no colorprofile and PS is set to not ask about missing 
profiles.

C. There is no color shift. PS displays it correctly.

 

 

From: softimage-boun...@listproc.autodesk.com 
[mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Sebastien Sterling
Sent: Friday, February 12, 2016 5:39 PM
To: softimage@listproc.autodesk.com
Subject: Re: Softimage and CMYK

 

The problem here is that the cmyk image already has a decoloration when I bring 
the .PDF into photoshop no matter what profiles I use there is still that 
basterding color shift.

On 12 Feb 2016 15:50, "Jason S"  wrote:

I found out when wanting to copy the lightness channel from the CMYK image 
converted to lab to paste it in an RGB ver, and saw that just converting all of 
it from there to RGB seemed to do the trick.

Maybe because as lab works with a lightness channel, it doesnt need to do any 
specific curve manipulations to recreate levels in another space
   but go figure.

nevertheless, hope that can work!
J

On 02/12/16 10:13, Jason S wrote:

You can have CMYK images in 16 or 32 too, but if your sources are 8 bit, it can 
be fine if there aren't too wide gradients or making wild corrects.

But here's what seems to work,

converting from CMYK -> Lab Color  seems to keep all levels as they were, 
and then from Lab Color -> to RGB  ... also seems to keep all levels as they 
were!

(It might be best to convert to 16bit (if they were in 8) before doing so.)

Cheers,
J

On 02/12/16 10:08, Sebastien Sterling wrote:

I think it has to do with RGB being additive; adding all colors leads to white

and CMYK being subtractive. adding all colors leads to black

RGB has so many more colors, it must be like clamping the bit depth but not 
quite.

at any rate you loose something going one way, so it is a destructive workflow.

 

On 12 February 2016 at 14:55, Jason S  wrote:

It weird because if you take screenshot while in CMYK colorspace and paste in 
an RGB image, 
there you go, same blacklevels and everything as in CMYK but in RGB space.

So would there be a way to "bake" color info from one colorspace to another?
(assuming it's for hirez images, otherwise you could just take screenshots :P )

I find it surprising that something like photoshop cant manage to make a 1:1 
conversion.


On 02/11/16 18:19, Sebastien Sterling wrote:

Have been doing variants of this, to no great success, it doesn't seem to want 
to change anything, haven't tried absolute colometric though, maybe i will try 
that. The Web converter actually does have an effect, but not perfect, it does 
bring the ultramarines back towards black.

 

On 11 February 2016 at 23:02, Sven Constable  wrote:

Photoshop Edit->Convert To Profile

You will see the source color space embedded in the original (if there is any) 
and the target color space.

Choose  one of the RGB spaces (eg. sRGB).

Check blackpoint compensation and Relative Colometric.

Tick Preview to see the result.

Ideally you should see no to minimal color shifting, but this depends on the 
original color profile within the CMYK file.

 

I'm pretty sure this what you'll get with that web based converter.

However, your problem is not to get a close color match but to change colors 
(ultramarine blue to black). Not sure if this is possible without manual 
grading but you can try unchecking black point compensation and switch to 
Absolute Colometric. Then switch through the different color profiles and see 
if any of it will change the ultramarine blue back to black.

If this worked somehow, do a second conversion to sRGB with blackpoint 
compensation ON and relative colometric.

 

If this won't work, I think there is only manual color grading or have the 
client send you "correct" files.

 

sven

 

 

 

 

 

 

Re: Softimage and CMYK

[Sebastien Sterling]

The problem here is that the cmyk image already has a decoloration when I
bring the .PDF into photoshop no matter what profiles I use there is still
that basterding color shift.
On 12 Feb 2016 15:50, "Jason S"  wrote:

> I found out when wanting to copy the lightness channel from the CMYK image
> converted to lab to paste it in an RGB ver, and saw that just converting
> all of it from there to RGB seemed to do the trick.
>
> Maybe because as lab works with a lightness channel, it doesnt need to do
> any specific curve manipulations to recreate levels in another space
>but go figure.
>
> nevertheless, hope that can work!
> J
>
> On 02/12/16 10:13, Jason S wrote:
>
> You can have CMYK images in 16 or 32 too, but if your sources are 8 bit,
> it can be fine if there aren't too wide gradients or making wild corrects.
>
> But here's what seems to work,
>
> converting from CMYK -> Lab Color  seems to keep all levels as they were,
> and then from Lab Color -> to RGB  ... also seems to keep all levels as
> they were!
>
> (It might be best to convert to 16bit (if they were in 8) before doing so.)
>
> Cheers,
> J
>
> On 02/12/16 10:08, Sebastien Sterling wrote:
>
> I think it has to do with RGB being additive; adding all colors leads to
> white
>
> and CMYK being subtractive. adding all colors leads to black
>
> RGB has so many more colors, it must be like clamping the bit depth but
> not quite.
>
> at any rate you loose something going one way, so it is a destructive
> workflow.
>
> On 12 February 2016 at 14:55, Jason S  wrote:
>
>> It weird because if you take screenshot while in CMYK colorspace and
>> paste in an RGB image,
>> there you go, same blacklevels and everything as in CMYK but in RGB space.
>>
>> So would there be a way to "bake" color info from one colorspace to
>> another?
>> (assuming it's for hirez images, otherwise you could just take
>> screenshots :P )
>>
>> I find it surprising that something like photoshop cant manage to make a
>> 1:1 conversion.
>>
>>
>> On 02/11/16 18:19, Sebastien Sterling wrote:
>>
>> Have been doing variants of this, to no great success, it doesn't seem to
>> want to change anything, haven't tried absolute colometric though, maybe i
>> will try that. The Web converter actually does have an effect, but not
>> perfect, it does bring the ultramarines back towards black.
>>
>> On 11 February 2016 at 23:02, Sven Constable 
>> wrote:
>>
>>> Photoshop Edit->Convert To Profile
>>>
>>> You will see the source color space embedded in the original (if there
>>> is any) and the target color space.
>>>
>>> Choose  one of the RGB spaces (eg. sRGB).
>>>
>>> Check blackpoint compensation and Relative Colometric.
>>>
>>> Tick Preview to see the result.
>>>
>>> Ideally you should see no to minimal color shifting, but this depends on
>>> the original color profile within the CMYK file.
>>>
>>>
>>>
>>> I'm pretty sure this what you'll get with that web based converter.
>>>
>>> However, your problem is not to get a close color match but to change
>>> colors (ultramarine blue to black). Not sure if this is possible without
>>> manual grading but you can try *unchecking black point compensation*
>>> and switch to *Absolute Colometric*. Then switch through the different
>>> color profiles and see if any of it will change the ultramarine blue back
>>> to black.
>>>
>>> If this worked somehow, do a second conversion to sRGB *with blackpoint
>>> compensation ON and relative colometric*.
>>>
>>>
>>>
>>> If this won't work, I think there is only manual color grading or have
>>> the client send you "correct" files.
>>>
>>>
>>>
>>> sven
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
>

Re: Softimage and CMYK

[Jason S]

  
  
I found out when wanting to copy the
  lightness channel from the CMYK image converted to lab to paste it
  in an RGB ver, and saw that just converting all of it from there
  to RGB seemed to do the trick.
  
  Maybe because as lab works with a lightness channel, it doesnt
  need to do any specific curve manipulations to recreate levels in
  another space
     but go
  figure.
  
  nevertheless, hope that can work!
  J
  
  On 02/12/16 10:13, Jason S wrote:


  
  You can have CMYK images in 16 or 32
too, but if your sources are 8 bit, it can be fine if there
aren't too wide gradients or making wild corrects.

But here's what seems to work,

converting from CMYK -> Lab Color  seems to keep all levels
as they were, 
and then from Lab Color -> to RGB  ... also seems to keep all
levels as they were!

(It might be best to convert to 16bit (if they were in 8) before
doing so.)

Cheers,
J

On 02/12/16 10:08, Sebastien Sterling wrote:
  
  

  

  I think it has to do with RGB being additive; adding
all colors leads to white

  
  and CMYK being subtractive. adding all colors leads to
  black
  

RGB has so many more colors, it must be like clamping the
bit depth but not quite.

  
  at any rate you loose something going one way, so it is a
  destructive workflow.


  On 12 February 2016 at 14:55, Jason S

wrote:

  
It weird because if you take screenshot while in
  CMYK colorspace and paste in an RGB image, 
  there you go, same blacklevels and everything as in
  CMYK but in RGB space.
  
  So would there be a way to "bake" color info from one
  colorspace to another?
  (assuming it's for hirez images, otherwise you could
  just take screenshots :P )
  
  I find it surprising that something like photoshop
  cant manage to make a 1:1 conversion.


On 02/11/16 18:19, Sebastien Sterling wrote:
  

  
Have been doing variants of this, to
  no great success, it doesn't seem to want to
  change anything, haven't tried absolute colometric
  though, maybe i will try that. The Web converter
  actually does have an effect, but not perfect, it
  does bring the ultramarines back towards black.


  On 11 February 2016 at
23:02, Sven Constable 
wrote:

  

  Photoshop


  Edit->Convert To Profile
  You


  will see the source color space
  embedded in the original (if there is
  any) and the target color space.
  Choose


   one of the RGB spaces (eg. sRGB).
  Check


  blackpoint compensation and Relative
  Colometric.
  Tick


  Preview to see the result.
  Ideally


  you should see no to minimal color
  shifting, but this depends on the
  original color profile within the CMYK
  file.
   
  I'm


  pretty sure this what you'll get with
  that web based converter.
  However,


  your problem is not to get a close
  color match but to change colors
  (ultramarine blue to black). Not sure
  if this is possible without manual
  grading but you can try unchecking
black point compensation and
  

Re: Softimage and CMYK

[Jason S]

  
  
You can have CMYK images in 16 or 32
  too, but if your sources are 8 bit, it can be fine if there aren't
  too wide gradients or making wild corrects.
  
  But here's what seems to work,
  
  converting from CMYK -> Lab Color  seems to keep all levels as
  they were, 
  and then from Lab Color -> to RGB  ... also seems to keep all
  levels as they were!
  
  (It might be best to convert to 16bit (if they were in 8) before
  doing so.)
  
  Cheers,
  J
  
  On 02/12/16 10:08, Sebastien Sterling wrote:


  

  
I think it has to do with RGB being additive; adding
  all colors leads to white
  

and CMYK being subtractive. adding all colors leads to black

  
  RGB has so many more colors, it must be like clamping the bit
  depth but not quite.
  

at any rate you loose something going one way, so it is a
destructive workflow.
  
  
On 12 February 2016 at 14:55, Jason S 
  wrote:
  

  It weird because if you take screenshot while in CMYK
colorspace and paste in an RGB image, 
there you go, same blacklevels and everything as in CMYK
but in RGB space.

So would there be a way to "bake" color info from one
colorspace to another?
(assuming it's for hirez images, otherwise you could
just take screenshots :P )

I find it surprising that something like photoshop cant
manage to make a 1:1 conversion.
  
  
  On 02/11/16 18:19, Sebastien Sterling wrote:

  

  Have been doing variants of this, to no
great success, it doesn't seem to want to change
anything, haven't tried absolute colometric though,
maybe i will try that. The Web converter actually
does have an effect, but not perfect, it does bring
the ultramarines back towards black.
  
  
On 11 February 2016 at
  23:02, Sven Constable 
  wrote:
  

  
Photoshop

Edit->Convert To Profile
You

will see the source color space embedded
in the original (if there is any) and
the target color space.
Choose

 one of the RGB spaces (eg. sRGB).
Check

blackpoint compensation and Relative
Colometric.
Tick

Preview to see the result.
Ideally

you should see no to minimal color
shifting, but this depends on the
original color profile within the CMYK
file.
 
I'm

pretty sure this what you'll get with
that web based converter.
However,

your problem is not to get a close color
match but to change colors (ultramarine
blue to black). Not sure if this is
possible without manual grading but you
can try unchecking black point
  compensation and switch to Absolute
  Colometric. Then switch through
the different color profiles and see if
any of it will change the ultramarine
blue back to black.
If

this worked somehow, do a second
conversion to sRGB with blackpoint
  compensation ON and relative
  colometric.
 
If

this won't work, I think there is only
manual color grading or have the client
send you "correct" files

Re: Softimage and CMYK

[Sebastien Sterling]

I think it has to do with RGB being additive; adding all colors leads to
white

and CMYK being subtractive. adding all colors leads to black

RGB has so many more colors, it must be like clamping the bit depth but not
quite.

at any rate you loose something going one way, so it is a destructive
workflow.

On 12 February 2016 at 14:55, Jason S  wrote:

> It weird because if you take screenshot while in CMYK colorspace and paste
> in an RGB image,
> there you go, same blacklevels and everything as in CMYK but in RGB space.
>
> So would there be a way to "bake" color info from one colorspace to
> another?
> (assuming it's for hirez images, otherwise you could just take screenshots
> :P )
>
> I find it surprising that something like photoshop cant manage to make a
> 1:1 conversion.
>
>
> On 02/11/16 18:19, Sebastien Sterling wrote:
>
> Have been doing variants of this, to no great success, it doesn't seem to
> want to change anything, haven't tried absolute colometric though, maybe i
> will try that. The Web converter actually does have an effect, but not
> perfect, it does bring the ultramarines back towards black.
>
> On 11 February 2016 at 23:02, Sven Constable 
> wrote:
>
>> Photoshop Edit->Convert To Profile
>>
>> You will see the source color space embedded in the original (if there is
>> any) and the target color space.
>>
>> Choose  one of the RGB spaces (eg. sRGB).
>>
>> Check blackpoint compensation and Relative Colometric.
>>
>> Tick Preview to see the result.
>>
>> Ideally you should see no to minimal color shifting, but this depends on
>> the original color profile within the CMYK file.
>>
>>
>>
>> I'm pretty sure this what you'll get with that web based converter.
>>
>> However, your problem is not to get a close color match but to change
>> colors (ultramarine blue to black). Not sure if this is possible without
>> manual grading but you can try *unchecking black point compensation* and
>> switch to *Absolute Colometric*. Then switch through the different color
>> profiles and see if any of it will change the ultramarine blue back to
>> black.
>>
>> If this worked somehow, do a second conversion to sRGB *with blackpoint
>> compensation ON and relative colometric*.
>>
>>
>>
>> If this won't work, I think there is only manual color grading or have
>> the client send you "correct" files.
>>
>>
>>
>> sven
>>
>>
>>
>>
>>
>
>

Re: Softimage and CMYK

[Jason S]

  
  
It weird because if you take screenshot
  while in CMYK colorspace and paste in an RGB image, 
  there you go, same blacklevels and everything as in CMYK but in
  RGB space.
  
  So would there be a way to "bake" color info from one colorspace
  to another?
  (assuming it's for hirez images, otherwise you could just take
  screenshots :P )
  
  I find it surprising that something like photoshop cant manage to
  make a 1:1 conversion.
  
  
  On 02/11/16 18:19, Sebastien Sterling wrote:


  Have been doing variants of this, to no great
success, it doesn't seem to want to change anything, haven't
tried absolute colometric though, maybe i will try that. The Web
converter actually does have an effect, but not perfect, it does
bring the ultramarines back towards black.
  
  
On 11 February 2016 at 23:02, Sven
  Constable 
  wrote:
  

  
Photoshop
Edit->Convert To Profile
You
will see the source color space embedded in the
original (if there is any) and the target color
space.
Choose
 one of the RGB spaces (eg. sRGB).
Check
blackpoint compensation and Relative Colometric.
Tick
Preview to see the result.
Ideally
you should see no to minimal color shifting, but
this depends on the original color profile within
the CMYK file.
 
I'm
pretty sure this what you'll get with that web based
converter.
However,
your problem is not to get a close color match but
to change colors (ultramarine blue to black). Not
sure if this is possible without manual grading but
you can try unchecking black point compensation
and switch to Absolute Colometric. Then
switch through the different color profiles and see
if any of it will change the ultramarine blue back
to black.
If
this worked somehow, do a second conversion to sRGB
with blackpoint compensation ON and relative
  colometric.
 
If
this won't work, I think there is only manual color
grading or have the client send you "correct" files.
 
sven
 

  
 

  

  

  


  

Aborting commands (C++)

[Mathias N]

I have been trying to use the OnEvent callback with siOnBeginCommand to
abort and replace ApplyTopoOp commands in SI2013

Building on the example in the SDK documentation

I am successfully intercepting events, but only some of them abort
correctly, returning

> ' INFO : 4373 - This event was aborted:
>
before executing the command anyway.

CreatePrim and ApplyTopoOp, for instance, behave this way. Other commands,
such as selection and navigation commands, abort successfully.

Code when attempting to abort ApplyTopoOp:

> XSIPLUGINCALLBACK CStatus HCoverrideCommand_OnEvent( CRef& in_context ){
>
> Application app;
> Context ctxt(in_context);
> Command currentCommand = ctxt.GetAttribute("Command");
> CString commandName = currentCommand.GetName();
>
> if (commandName=="Extrude Comp. Axis")
> {
> app.LogMessage("Extrude detected. Attempting to abort.");
>
> //Abort command.
> return CStatus::OK;
>
> }
>
> //Return false to NOT cancel the intercepted command
> return CStatus::False;}
>
> Output:

> ' INFO : Extrude detected. Attempting to abort.
> ' INFO : 4373 - This event was aborted:
> ' 
> '  C:\Users\Roughy\Autodesk\Softimage_2013\Addons\HairCommands\Application\Plugins\hairCommands.dll>
> '
> ApplyTopoOp "ExtrudeComponentAxis", "grid.poly[27,28,35,36]",
> siUnspecified, siPersistentOperation


 Are you only allowed to abort certain commands, or am I doing something
wrong here?

The docs also state that you can modify the arguments of the command.
I don't quite see how to do so, unless you're expected to abort the command
and call its replacement yourself.

Any help would be greatly appreciated.