Nuke; Basic Workflows; Gizmo Advanced - PartB Video Lecture | Create Visual Effects with Nuke - Professional Skills

next let's actually go back to the group
node and give ourselves a UI widget for
the control to change between two color
spaces so I'll right-click anywhere in
the node graph in the in the panel go
back to our manage user knob manager and
right under the channels knob I'm gonna
create or add this time add an empty
interface widget and I want a pulldown
choice menu I'm gonna call that
operation and in this case I'll just
leave the label blank if the label is
left blank it'll just reuse the name of
the knob that I'm creating the name is
the one that you want to reference in
expressions so keep that in mind and the
first item of our pulldown list is going
to be HSV and the second one H is L hit
OK and let's call that done and now you
can see we have a nice drop-down list
here so now we just need to provide some
control and link to that knob by
creating a switch node that lets us
switch from one part of the tree to the
other and because HSV is our first item
in the list I'm going to make sure that
the pipe zero is connected to HSV and
pipe one is connected to HS l and now I
can simply right-click in the switch
node and look into the which knob add an
expression and now link it to our
operation knob that we created and
because the operation knob lives in the
parents panel in the group's panel we
have to reference it by the prefix
parent dot followed by the actual node
name like so and now you can see when I
switch the drop-down list here we
actually control the internal switch
node and that gives us a different color
space option so let's see what that
actually does to our gizmo
this is the HSL output this is the HSV
output so you can see it's a quite
significant difference and depending on
what you need to do one or the other
might work for you best and because we
can let's just add a third one I'm just
going to go in here
hook that up again and this time I'm
going to use the lav color space because
that's kind of handy to have because the
LAV color space is trying to mimic the
luminance perception of the human eye a
bit more accurately so that might
actually be a good option to have
however this guy puts the luminance L
into the red Channel
so before we pipe that up into our
downstream we have to shuffle that
luminance from the red channel to the
blue channel because we're copying the
blue channel as a luminance over here so
let's create a shuffle node to do that
one of the scariest guys in nuke I guess
and we want the output to be blue and
the blue channel should become should
come from the red Channel so this
basically shuffles the red channel into
the blue Channel and now we're ready to
just type that into the switch node and
because this guy now has three inputs
we'll go back to the groups panel and
we'll go back into our operation knob
and we'll add L a B as the third option
and now let's investigate that again
this is la la vie this is HSL this is
HSV so now we've got three different
options for the user to play with
including the lookup curves and the
actual channel controls and in case you
hadn't noticed I called the whole knob
operation because operation is another
note knob name that actually triggers
noose order label function and that
gives us some information about the
knobs setting in the node graph which
I'm a big fan of so let's save some
defaults here I'll put this to Li B and
actually I'm gonna push that
pre-multiply option we created in the
previous tutorial and push that up
alright just down here and the last
thing I want to do is to leave some
useful information in my gizmos so I'll
right-click here anywhere and then in
the panel again and go to edit help and
this will become the gizmos health
information that will be displayed when
the user hits that little question mark
up here so let's put something useful in
here
confirm that and we finally go back to
our note tab hit exporters gizmo
and I'm just gonna overwrite my gizmo
file here if you do this make sure that
that particular gizmo file is not used
by anybody including yourself in
existing comp scripts otherwise you
might break the existing work so it's
it's a good idea to always keep a
developer's copy offline that you work
on and if in doubt version up but in
this case I'm just gonna overwrite the
gizmo file here confirm that and delete
the group once again I'm just gonna go
to file script command and type the name
of Archaea to pull that gizmo file back
in that we just created and here it is
with our new interface with the new
order label functions and with all the
new features
you