hello and welcome to our render
Channel's quick start video for V for
Revit in this video we'll go over how to
Output render channels for flexibility
to improve your workflow a render
channel is a render output that contains
a specific part of the image's
information such as distinguishing just
the Reflections in the scene for example
this enables you to adjust specific
components of of a rendered image in
compositing or image editing to give you
incredible control over the final
quality of your output without the need
to reender the project launch Revit and
load the project file channels. rvt from
the downloaded assets from this
tutorial's web page linked below you'll
be able to use this project with Revit
versions 2015 and up with the project
loaded go into the vray tab and click
the setting icon to load some settings
select sharing and click on load
settings and load the file channels. XML
from the downloaded assets click import
selected change the current view to
render set quality to medium and set
resolution to crop region with printer
set to a DPI of
300 now feel free to choose a resolution
setting that fits your system's Comfort
level click settings and click on fog
turn on aerial perspective and set the
view distance to 8,000 M the interface
will automatically convert 8,000 M to
whatever units you're using in our case
feet now click on engine change the
image sampler from Progressive to
buckets you can do it just for the
medium setting but I'll do all of them
here just for fun now let's talk about
channels click channels for the render
channel settings go ahead and turn on
all the render channels available here
I'll go over most of them as we continue
in the
tutorial rendering in channels will not
impact the render time very much at all
but the flexibility you gain for editing
the image after the fact is pretty
substantial in the render channel
settings enable the D noiser Channel
this channel is essentially a
post-processing effect that reduces
noise in
renders first leave the mode to generate
D noise Channel as opposed to replace
RGB channel to see the difference
between the original raw render and the
denoised
result the radius preset allows you to
set how much denoising you want though
you can also enter more specific values
as well turn on used GPU if you have a
powerful video card to make the process
a bit faster now turn on zdepth channel
this generates a grayscale image that
gives a brightness value in the red
which shows the distance a surface is
away from the camera now this is useful
for number of compositing effects such
as depth of field or adjusting the look
of your
atmosphere so we will set the white
point of the zdepth to be at 12 feet
from the camera and the Black Point to
be at 26 ft now these values I'm
entering are in the Project's units if
you're set to meters these will
represent 12 M and 26 M respective
we're of course working in feat so I'll
leave these at 12 and
26 close the settings window I'm going
to enable swarm to make the rendering
faster enable swarm if you have it
installed and set up otherwise you can
leave this off you do not need to have
swarm for render channels to work click
render I'm adding machines to the Swarm
now to speed up the render and I'll let
this go for a while and elaps the time
to get the result back for you as the
render resolves it then kicks into the D
noiser pass as you can see here in the
progress window and now the render is
complete now let's go over the different
channels that we just
output in the upper left of the vfb is
the channel list selecting a channel
here displays its result in the
vfb RGB color is essentially your final
render in all its Glory
the alpha channel is a mat that shows
where Solid Surfaces are in the scene as
white we can see here through the window
to the sky so that part of the alpha
channel is black which denotes
transparency or even empty
space some render channels are Advanced
workflows for a lot of control in the
composite so let's just go over the
primary channels that when properly
combined in image editing like with
Photoshop or after effects reassemble
into the final RGB render often called
the
beauty the diffused channel is the flat
color of the project devoid of any
lighting or other surface properties
like
Reflections Global illumination is the
lighting contribution from bounced light
in the scene while lighting is the
contribution from the direct Lighting in
the project which in this case is the
sun reflection isolates the reflections
rendered into the surfaces per their
materials while refraction shows parts
of the image that are shown through
refractive objects such as glass in this
case the
windows self-illumination shows objects
that have illuminated
materials here our lampshades material
was set to emit some illumination so
they show up in this
channel the specular Channel shows the
reflection of highlights in the scene
from light sources which again is the
sun in this project
this adds the gloss for example to these
leather
seats the background is the direct line
of sight to the background of the
project this blue sky the atmosphere
Channel stores any aerial perspective or
environment fog that you added to the
scene for us it was the aerial
perspective that we enabled you can of
course save out these channels as their
own images through the vfbs save icon
seen
here now all those channels we talked
about when composited together properly
will get you right back to the RGB color
render but this workflow gives you a
huge latitude to adjust any component
along the way like if you wanted to
increase or tint the Reflections in the
floor without rendering the entire
project now if you had swarm enabled Dr
buckets will show you which machine
rendered what part of the image which is
great for troubleshooting if needed the
zdepth Channel shows the relative
distance surfaces are from the camera
with white values being closes to the
camera and the black and even negative
values pushing further back in space
this is very useful for compositing
depth of field and other atmospheric
effects in composite
plugins now the denoise channel and
those other channels below it are what
vray generates to help denoise and clean
clean up the render without needing to
have prolonged render times with very
high quality values when you click on
the D noiser Channel you essentially get
a new RGB Channel but with less noise
than the original RGB pass I'll zoom
into this table here to show the
difference D noiser makes in this render
when I switch back to the RGB Channel
you can easily see the grain pop back
into the image back to the D noiser
Channel and all that rainy noise is
removed compare the results of this
painting the painting has a bump map
apply to give it a textured look the
denoiser softens the bump slightly when
removing noise from this area the more
noise and image has before the D noiser
pass runs the more detail could
potentially be removed by the denoiser
itself therefore if you use a lower
quality setting in the quality settings
in the v-ray ribbon you may lose a
little textured data now move around
your image and switch between the RGB
and D noiser channels to compare how the
denoiser cleaned up your image without
adding a whole lot of render time using
render channels and image editing after
a render gives you great control over
your final
output now we'll go over how to assemble
the render channels back together in a
following tutorial video as well as on
our documentation website at doc.
chaosgroup
tocom thank you for joining us for this
quick start video on render channels in