Re: [Gimp-user] MIDI controllers for controlling brush size and colors [was: Save Export Complaints]

[Ryan Stark <effluxion googlemail com>]

Hi.

I've not been on my Linux system with Gimp for a bit so Ideally I need
to work through exactly how I set that up and how I'm using it. The
aconnectgui is how to see and make the connections but in actual fact
it's best to do that from command. The connection isn't remembered so
rather than set it up via aconnectgui I just run a command every time
I start Gimp.

As for the colour adjustments. You turn knobs to change colours but
you see that colour changing on the colour wheel and can still select
there anyway, if you want. It can be used to make small colour changes
as you paint or values, opacity, whatever you want. Brush size is an
obvious one. You can literally change stuff as you paint a stroke but
that can end up a bit glitchy. One problem with Gimp 2.8 is that the
top size of the brush is far too big. If you compile from scratch you
can change that. This needs to be mentioned in the Gimp developer
list. It's also possible to have UI to set that largest size of brush
so it's not too big. I've seen the code that needs added to do that.
This all needs to be better sorted out to make Gimp more ideal for
painting.These are simple changes that need to be in Gimp. Changing it
and compiling is too much trouble.

All the functions that can be mapped to keyboard can be mapped to MIDI
except the MIDI has continuous controller meaning instead of one key
command ton say make a brush bigger you have values from 0-127.
Obviously this is better. I mentioned that with colour I think you
need to set the controller to not go to value 0. I'll have to confirm
that but I think value 0 for a colour causes it to turn all colours to
0 or something similar. There is some kind of problem with that. I
think it needs to be 1-127.

Maybe some other people can have a go with this. Any piece of modern
music gear tends to have MIDI so if you've got any keyboard or
whatever you can test this or use software that can send MIDI to test
it. An example would be ZynAddSubFX. That should show up at ALSA and
it should have some MIDI out function (I Think). This would obviously
be useless but can used used just as a test. Until I get back into
Gimp for painting again, I can't explain everything.

On 12 September 2012 18:49, yahvuu <yahvuu gmail com> wrote:
> Hello Ryan,
>
> Am 12.09.2012 15:25, schrieb Ryan Stark:
> > [..] Gimp can be hooked up to a MIDI controller for
> > controlling brush sizes or anything else. This is a superb feature.
> > You can buy a little MIDI controller with lots of knobs and sliders.
> > VASTLY superior to sliders on graphics tablets.
>
>
>
> Und Am 12.09.2012 18:31, schrieb Ryan Stark:
> > > "Now that's a really neat idea.  What (affordable) MIDI controller do you
> > > like?"
> >
> >
> > I use a Korg NanoKontrol. The one here with the sliders and knobs:
> >
> > http://www.korg.co.uk/products/software_controllers/nano2/sc_nano2.php
> >
> > I'm not sure how much it is but it's cheap compared to what there used
> > to be. It's very small and portable so ideal for Gimp. It communicates
> > with alsa (via USB). You have a small GUI app called aconnectgui where
> > you can see the Korg output and Gimp input. You just connect them up.
> > I actually do it from command but that's because I couldn't find
> > aconnectgui in the Arch repo. Here's some info from the Ubuntu site:
> >
> > https://apps.ubuntu.com/cat/applications/precise/aconnectgui/
> >
> > One problem is that you need the Korg editor (Windows or OSX) to
> > change MIDI functions on the NanoKontrol. That should work via wine
> > but I didn't try that. The reason you have to change some things is
> > that by default some of the switches are momentary or maybe that
> > wasn't the problem. I can't remember exactly but I had to edit a few
> > things. I'm not on Linux at the moment to look at it exactly but
> > you'll find MIDI under Input controllers in Gimp. You have a vast
> > choice of Gimp parameters and you set them by choosing the one you
> > want then moving the appropriate knob on the controller to set it to
> > the parameter. There is stacks you can do. I like to set it to change
> > colours i.e. one knob will increase red etc. Selecting colours, values
> > etc in the colour wheel suddenly starts to become obsolete. Actually,
> > thinking about that particular function, I think that was why I had to
> > edit the Korg via its OSX(or Windows) editor. I think you need that
> > particular value to not go to zero value. Probably I should document
> > all this somewhere properly.  The huge advantage over a graphics
> > tablet slider is that MIDI has continuous controllers. This means you
> > move the knobs and sliders up and down to exact values. You are not
> > sending a keyboard command. It's really quite ingenious whoever
> > thought of adding that to Gimp and I bet hardly anyone uses it.
>
>
> even more so since this really interesting piece of information got buried
> in one of
> those threads i really cannot justify spending my time to wade through such
> slurry :)
>
>
> I'm really curious about the following passage:
> > [..] I like to set it to change
> > colours i.e. one knob will increase red etc. Selecting colours, values
> > etc in the colour wheel suddenly starts to become obsolete.
>
>
> How is your setup working here?
> Can you still you use the colour wheel (via mouse/tablet) in parallel?
> How do you keep the slider/knob position in sync with the current color
> then?
>
> Is there a kind of adjustment that the controller offers the most advantage
> for you?
> I'm thinking here of relative vs. absolute adjustments, that is
>    - a "bit more of blue", or a little darker vs,
>    - all RGB sliders down: instantly gives black;  all three sliders at 50%:
> perfect mid gray.
>
> I mean, one compelling advantage of using the color wheel is that you can
> see all available colors in
> advance, before choosing one of them.
>
>
> best regards,
> peter