[Bf-compositor] Clamping (Mix, Math, RGB Curves)

Wed May 28 14:15:05 CEST 2014

Hey Diego,
I successfully added the driver,
I got the problem in the path of the RGB..
Here the picture I made to explain the problem:

https://lh6.googleusercontent.com/-k6GDiWl4uNU/U4XRy1AzQ_I/AAAAAAAAJy8/C-xuqUDrNKM/w1357-h784-no/value.jpg

I forgot to open the panel in the left of the drivers ..
 I'm working on the red channel of the ramp and I was trying to evaluate
the red value of the RGB node that is perfectly showed in the python
console but as you can see return a red background on the path of the
driver....

Am I missing something?

2014-05-28 13:15 GMT+02:00 Diego Gangl <dnicolas at gmail.com>:

> Hey,
>
> Nice work on those nodegroups, I'd like to see them too. It would be
> great to have some kind of standard library of nodes for motion/video
> work in the compositor with stuff like this.
>
> Francesco,
> Have you tried the outliner workaround for problem #2? You'd have to
> find the node in the outliner, then the socket, select it and press D
> to add the driver. Btw, it doesn't change color in the ui sometimes.
>
> I tried the nodes addon but I get a missing paths error, maybe it
> hasn't been updated?
>
> Cheers,
>
> 2014-05-28 7:15 GMT-03:00 Francesco Paglia <f.paglia.80 at gmail.com>:
> > Hey Sean,
> > I'm really interested in seeing your node and much more on the match
> color
> > node...
> > I've tried by myself making one but I couldn't find a nice way to have
> the
> > setup embedded in a node group.
> >
> > Looking at the tutorial the artist simply match low and hi valuse of a
> > levels effects for each channel.
> > So I though I can mimic that result just with a simple setup:
> > 1. separate RGB  of the input,
> > 2. add a color ramp to each channel (to get a remap of Hi and LOW value)
> > 3. add a combine channel to recreate the final image
> >
> > The result looked promising but
> > 1. to expose the value of the ramp you have to add a driver on each stop
> of
> > the ramp
> > 2. the driver (don't know why) in official 2.70 build seems cannot read
> the
> > value of a node RGB.output or the input of the group even if it is
> readable
> > in the python console (the driver simply show the path background in red
> > color)
> > 3. value are clamped in the 0-1 range so if values exceed this range they
> > are remapped.. (well this is a known side effect driven by the node
> used...)
> >
> > I'm curious to know your approach :)
> > Thanks,
> > Francesco
> >
> >
> > 2014-05-28 7:57 GMT+02:00 David McSween <3pointedit at gmail.com>:
> >
> >> I would certainly be interested in a 'colour matcher' node group.
> >> Especially if it Rock My World as Mark says in the link ;-)
> >>
> >> These look really useful, it would be great if everyone could at least
> >> match pedestal across their elements.
> >>
> >>
> >> On Wed, May 28, 2014 at 2:07 PM, Sean Kennedy <mack_dadd2 at hotmail.com>
> >> wrote:
> >>>
> >>> Hey guys,
> >>>
> >>> I made a few nodegroups we were discussing.
> >>>
> >>>
> https://www.dropbox.com/s/uj9kw6dm1sp3cot/clamp_nodes_screenshot_02.jpg
> >>>
> >>> I made a Value clamp, as Deigo had made. Then I made a RGB clamp, where
> >>> you can set R, G, and B individually. And then I made the node I really
> >>> wanted, a black levels node.
> >>>
> >>> When you're compositing one image over another, and they come from two
> >>> different sources, they usually have completely different color values
> in
> >>> the highs and lows (obviously, we all know this). At R&H, we had a
> great
> >>> Black Levels node where we could simply sample a dark spot of a
> background
> >>> plate, and the darks of the foreground plate would just shift to
> match. This
> >>> works the same exact way. It was ideal for CG elements going over live
> >>> action plates, because usually the general highs and overall color of
> the CG
> >>> matched the plate fine, but the blacks always came in as absolute
> blacks, or
> >>> sometimes negative blacks. This node made fixing it a 1-click
> operation.
> >>>
> >>> If anyone is interested, I can upload a blend file with the nodegroups.
> >>> The clamps are super easy to make, though. But maybe the black levels
> one
> >>> would be interesting to someone?
> >>>
> >>> Tomorrow I'm going make a node setup to easily replicate Mark
> >>> Christiansen's techniques for matching the general colors of one plate
> to
> >>> another. You can see the technique here in the free sample videos, if
> you're
> >>> interested.
> >>>
> >>>
> http://www.lynda.com/After-Effects-tutorials/After-Effects-Compositing-Essentials-Matching-Foreground-Background/114913-2.html
> >>>
> >>> It's fun making these!
> >>>
> >>> Sean
> >>>
> >>> ________________________________
> >>> From: f.paglia.80 at gmail.com
> >>> Date: Sun, 25 May 2014 09:50:01 +0200
> >>> To: bf-compositor at blender.org
> >>> Subject: Re: [Bf-compositor] Clamping (Mix, Math, RGB Curves)
> >>>
> >>> Thanks for the advices Diego and David!
> >>> Just a little thought:
> >>> Adding lot of nodegroups in a single "category" - I mean in the same
> menu
> >>> list - isn't that efficient... is there a way to manage their position
> in
> >>> the SHIFT+A menu?
> >>>
> >>> Referenced node group are quite "risky" since compositing session works
> >>> most likely WYSIWYG and as soon as you change something you have to
> check
> >>> back each project... but I get your point Diego... I'm very used to
> linked
> >>> group, they are so useful and I hope they will be empowered a lot with
> >>> gooseberry since Proxyfication have room for for lot of improvement.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> 2014-05-25 4:26 GMT+02:00 David McSween <3pointedit at gmail.com>:
> >>>
> >>> Don't forget the addon Node Presets
> >>>
> http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Compositing/Compositing_Presets
> >>> I think you can add node groups and store them in a portable file.
> >>>
> >>> On 25 May 2014 09:59, "Diego Gangl" <dnicolas at gmail.com> wrote:
> >>>
> >>> >> It is possible to clamp (blacks and whites individually even), but
> >>> >> whenever I want to do it I have to add gazillion nodes. It takes
> time.
> >>> >> My
> >>> >> intention is to make it with a single click.
> >>>
> >>> You can turn them into a group, plug the math values into group
> >>> inputs, name it and bam! your own Clamp Node that you can add from the
> >>> group menu.
> >>>
> >>> > Isn't there a way to develop few nodegroup store them somewhere and
> >>> > recall
> >>> > them in a personal group list or add them in the lists we already
> have?
> >>>
> >>> There's two ways:
> >>>
> >>> 1- Make the groups in a new (empty) blend file, then save it as your
> >>> start-up file (ctrl+U). The node groups will be available in every new
> >>> file you make.
> >>>
> >>> 2- Make a "Node Library" file. Make all your groups there, then make a
> >>> new empty file and link all the groups from the library file. Save it
> >>> as your start-up file and you get all the groups. The cool thing is
> >>> that if you tweak the groups inside the lib file, they will be upated
> >>> in all the blend files that link them.
> >>>
> >>> Gooseberry is going to bring a lot of developement into asset
> >>> management, so it will get better.
> >>>
> >>>
> >>> 2014-05-24 7:00 GMT-03:00 Francesco Paglia <f.paglia.80 at gmail.com>:
> >>> > Isn't there a way to develop few nodegroup store them somewhere and
> >>> > recall
> >>> > them in a personal group list or add them in the lists we already
> have?
> >>> > Could it be a python add-on?
> >>> > This would help us skip the tedious part of reloading those node
> every
> >>> > time
> >>> > a new blend file is created and also could help us distribute those
> >>> > nodes in
> >>> > their coherent place.
> >>> >
> >>> >
> >>> >
> >>> > 2014-05-24 11:31 GMT+02:00 Bartek Skorupa (priv)
> >>> > <bartekskorupa at bartekskorupa.com>:
> >>> >
> >>> >> It is possible to clamp (blacks and whites individually even), but
> >>> >> whenever I want to do it I have to add gazillion nodes. It takes
> time.
> >>> >> My
> >>> >> intention is to make it with a single click.
> >>> >> How much time did it take you to set up this fantastic node tree of
> >>> >> yours?
> >>> >> If it's more than one second - itś too much. It should be: Decision
> =>
> >>> >> 1
> >>> >> second later: DONE.
> >>> >>
> >>> >>
> >>> >> Bartek Skorupa
> >>> >>
> >>> >> www.bartekskorupa.com
> >>> >>
> >>> >> On 24 maj 2014, at 00:10, Sean Kennedy <mack_dadd2 at hotmail.com>
> wrote:
> >>> >>
> >>> >> Ah, great idea! We could even set one up with RGB, one on each
> >>> >> channel,
> >>> >> and save it as a nodegroup.
> >>> >> Thanks! So obvious, don't know why we didn't think of this. :)
> >>> >>
> >>> >> I'm going to set one up today.
> >>> >>
> >>> >> sean
> >>> >>
> >>> >> > From: dnicolas at gmail.com
> >>> >> > Date: Fri, 23 May 2014 19:07:28 -0300
> >>> >> > To: bf-compositor at blender.org
> >>> >> > Subject: Re: [Bf-compositor] Clamping (Mix, Math, RGB Curves)
> >>> >> >
> >>> >> > Hi all, I don't know how Blender's handles colors internally but
> >>> >> > wouldn't this work?
> >>> >> > http://www.pasteall.org/pic/show.php?id=71736
> >>> >> > (or are the V values already mapped to 0-1 from the separate
> node?)
> >>> >> >
> >>> >> > Cheers,
> >>> >> >
> >>> >> > 2014-05-23 18:46 GMT-03:00 Sean Kennedy <mack_dadd2 at hotmail.com>:
> >>> >> > > Could we set the value of the clamp? It could come in as
> defaults
> >>> >> > > of
> >>> >> > > 1.0 and
> >>> >> > > 0.0, but we could alter it to whatever we wanted. At R&H, most
> of
> >>> >> > > the
> >>> >> > > time
> >>> >> > > we clamped brights around 14-16. We'd only turn it down under
> that
> >>> >> > > if
> >>> >> > > we got
> >>> >> > > bad pixels when rendering.
> >>> >> > >
> >>> >> > > If you had a superbright red, like R 12, G 3, B 4, and you put a
> >>> >> > > clamp
> >>> >> > > of 1
> >>> >> > > on it, obviously it's going to set each value to 1, so what was
> >>> >> > > red
> >>> >> > > now
> >>> >> > > reads as white. But it would still be useful.
> >>> >> > >
> >>> >> > > After Effects clamp tool
> >>> >> >
> >>> >> > >
> >>> >> > > > >
> http://cdn.aescripts.com/media/catalog/product/cache/1/image/800x600/040ec09b1e35df139433887a97daa66f/f/t/ft-clamp-ui_1.png
> >>> >> > >
> >>> >> > > Nuke clamp is in the color grade node
> >>> >> >
> >>> >> > >
> >>> >> > > > >
> http://docs.thefoundry.co.uk/nuke/63/pythondevguide/_images/getMinMax_01.png
> >>> >> > >
> >>> >> > > I'm not posting the images to say "this is how we should do it",
> >>> >> > > but
> >>> >> > > rather,
> >>> >> > > to say it is useful and professional compositors would indeed
> use
> >>> >> > > it
> >>> >> > > often.
> >>> >> > >
> >>> >> > > In fact, I was working on a shot this week that could have used
> >>> >> > > it. I
> >>> >> > > was
> >>> >> > > given stock footage from a client, and I have no idea how much
> >>> >> > > they'll
> >>> >> > > color
> >>> >> > > correct it in post once I deliver the final vfx shot. SO I have
> to
> >>> >> > > make sure
> >>> >> > > all my blacks are in line with what is in the plate. I put a
> gamma
> >>> >> > > on
> >>> >> > > the
> >>> >> > > plate just to view the black levels and see how they match up
> when
> >>> >> > > pushed
> >>> >> > > really far.
> >>> >> > >https://dl.dropboxusercontent.com/u/10553822/clamp_blacks_01.jpg
> >>> >> > >
> >>> >> > > Since we don't have a clamp, I ended up putting a mix node right
> >>> >> > > after
> >>> >> > > the
> >>> >> > > stock footage node, setting it to Lighten, and making the color
> >>> >> > > over
> >>> >> > > it
> >>> >> > > black. then I slowly raised it while watching until the blacks
> all
> >>> >> > > came in
> >>> >> > > line. Would have been much easier to sample the value of the
> >>> >> > > darkest
> >>> >> > > dark I
> >>> >> > > wanted in the shot, throw a clamp node on with the black clamp
> set
> >>> >> > > to
> >>> >> > > those
> >>> >> > > values.
> >>> >> > >
> >>> >> > > In fact, at R&H, the Black Clamp node let you set an individual
> >>> >> > > value
> >>> >> > > for R,
> >>> >> > > G, and B. And it had a color picker so you could just sample the
> >>> >> > > image
> >>> >> > > and
> >>> >> > > the values would fill in automatically.
> >>> >> > >
> >>> >> > > Anyway, just throwing out my $0.02. Obviously I've found a
> >>> >> > > workaround
> >>> >> > > and
> >>> >> > > can live with it, but it would sure be great to someday see a
> >>> >> > > clamp
> >>> >> > > node.
> >>> >> > >
> >>> >> > > ________________________________
> >>> >> > > Date: Fri, 23 May 2014 14:21:40 -0700
> >>> >> > >
> >>> >> > > From: troy.sobotka at gmail.com
> >>> >> > > To: bf-compositor at blender.org
> >>> >> > > Subject: Re: [Bf-compositor] Clamping (Mix, Math, RGB Curves)
> >>> >> > >
> >>> >> > >
> >>> >> > > On May 23, 2014 1:56 PM, "Bartek Skorupa (priv)"
> >>> >> > > <bartekskorupa at bartekskorupa.com> wrote:
> >>> >> > >
> >>> >> > >> When I say: "clamp blacks" I always mean: set every value below
> >>> >> > >> 0.0
> >>> >> > >> to
> >>> >> > >> 0.0.
> >>> >> > >> When I say: "clamp whites" I always mean: set every value above
> >>> >> > >> 1.0
> >>> >> > >> to
> >>> >> > >> 1.0.
> >>> >> > >> Every compositing artist will know what I mean.
> >>> >> > >
> >>> >> > > If we can generate a clamp / scale node, I am all for it.
> >>> >> > >
> >>> >> > > I am saying there is no concept of white in a scene referred
> >>> >> > > model,
> >>> >> > > and as
> >>> >> > > such, you have to be careful as to not write nodes that break
> the
> >>> >> > > system.
> >>> >> > >
> >>> >> > > It is that simple. No white. No brighter than white. So sorry,
> >>> >> > > "Every
> >>> >> > > artist..." is actually "Every artist unfamiliar with HDR work."
> >>> >> > >
> >>> >> > > So a clamp node _must_ not make the erroneous assumption that
> 1.0
> >>> >> > > means
> >>> >> > > anything special, and rather provide for an arbitrary value
> range.
> >>> >> > >
> >>> >> > > If this all seems like speaking an alien language, it is
> precisely
> >>> >> > > why
> >>> >> > > I
> >>> >> > > chimed in and said "Whoa."
> >>> >> > >
> >>> >> > > There are already nodes that are broken because of erroneous
> >>> >> > > assumptions. It
> >>> >> > > would be a shame to make more.
> >>> >> > >
> >>> >> > > With respect,
> >>> >> > > TJS
> >>> >> > >
> >>> >> > >
> >>> >> > > _______________________________________________ Bf-compositor
> >>> >> > > mailing
> >>> >> > > list
> >>> >> > > Bf-compositor at blender.org
> >>> >> > > http://lists.blender.org/mailman/listinfo/bf-compositor
> >>> >> > >
> >>> >> > > _______________________________________________
> >>> >> > > Bf-compositor mailing list
> >>> >> > > Bf-compositor at blender.org
> >>> >> > > http://lists.blender.org/mailman/listinfo/bf-compositor
> >>> >> > >
> >>> >> > _______________________________________________
> >>> >> > Bf-compositor mailing list
> >>> >> > Bf-compositor at blender.org
> >>> >> > http://lists.blender.org/mailman/listinfo/bf-compositor
> >>> >> _______________________________________________
> >>> >> Bf-compositor mailing list
> >>> >> Bf-compositor at blender.org
> >>> >> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>> >>
> >>> >>
> >>> >>
> >>> >> _______________________________________________
> >>> >> Bf-compositor mailing list
> >>> >> Bf-compositor at blender.org
> >>> >> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>> >>
> >>> >
> >>> >
> >>> >
> >>> > --
> >>> > Francesco Paglia
> >>> > Vfx and Production Supervisor
> >>> >
> >>> > mobile  +39 347.82.12.473
> >>> > e-mail   f.paglia.80 at gmail.com
> >>> >
> >>> >
> >>> > _______________________________________________
> >>> > Bf-compositor mailing list
> >>> > Bf-compositor at blender.org
> >>> > http://lists.blender.org/mailman/listinfo/bf-compositor
> >>> >
> >>> _______________________________________________
> >>> Bf-compositor mailing list
> >>> Bf-compositor at blender.org
> >>> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>>
> >>>
> >>> _______________________________________________
> >>> Bf-compositor mailing list
> >>> Bf-compositor at blender.org
> >>> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>>
> >>>
> >>>
> >>>
> >>> --
> >>> Francesco Paglia
> >>> Vfx and Production Supervisor
> >>>
> >>> mobile  +39 347.82.12.473
> >>> e-mail   f.paglia.80 at gmail.com
> >>>
> >>>
> >>> _______________________________________________ Bf-compositor mailing
> >>> list Bf-compositor at blender.org
> >>> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>>
> >>> _______________________________________________
> >>> Bf-compositor mailing list
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> >>> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>>
> >>
> >>
> >> _______________________________________________
> >> Bf-compositor mailing list
> >> Bf-compositor at blender.org
> >> http://lists.blender.org/mailman/listinfo/bf-compositor
> >>
> >
> >
> >
> > --
> > Francesco Paglia
> > Vfx and Production Supervisor
> >
> > mobile  +39 347.82.12.473
> > e-mail   f.paglia.80 at gmail.com
> >
> >
> > _______________________________________________
> > Bf-compositor mailing list
> > Bf-compositor at blender.org
> > http://lists.blender.org/mailman/listinfo/bf-compositor
> >
> _______________________________________________
> Bf-compositor mailing list
> Bf-compositor at blender.org
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>

-- 
Francesco Paglia
Vfx and Production Supervisor

mobile  +39 347.82.12.473
e-mail   f.paglia.80 at gmail.com
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