The
other day I was trying to render a scene.
As a Max and Brazil rs user I know that
make a render wich involves a nice AA,
more than 3 light bounces, area shadows,
DOF, and more that 2500x3500 px of resolutionand
even more than 800,000 poligons need
a lot of patience and a lot of computer
power, since I just got a nice new computer
I inocently thought that this scene
will be a piece of cake for this computer,
but I was wrong, 3 days later the render
was just about the half way and I need
it for the next day at noon.
Well
I just canceled the render start change
some parmeters in a new test scene,
then I just remembered that somewhere
I read about some DOF (Z Depth) maps
and start asking in the forums, but
before I got an answer I start lookking
in Max help files and found the way
to render this kind of things so here
is what I learn.
First
you need your scene heres a simple
one you can download if you want.
Ok
adjust the params as you wish, I turn
the GI on 3 light bounces, 1 min and
2 max in the AA (I wont teach
how to use brazil) and this is what
you get.
This
is a nice render which is called Beauty
Render by some big companies lets
call it Difuse render (wow how original
I am).
Now
Aply a nice and neutral color to all
objects like white or even better black,
and change to the Default Scanline Render,
and in the Render Elements tab chose
Add...
Now
that you are in there, pick Z Depth
and Shadow and whaterver else that you
need (I just need shadow and DOF)
You
got 3 Virtual Frame Buffer one with
the render itself with the shadows and
color and stuff wich we dont need,
another wich is the shadow (a black
image with an alpha channel) and the
last the Z-depth buffer, save this 2
as tiff image file and turn on the option
of Store Alpha Channel.
See,
this was easy and relative fast. Now
go to PhotoShop CS (I'm not sure if
ver. 7 has the feature we need)
Ok
Now on PhotoShop open the 3 Images you
just save in Max.
Working
with in the Z Dept render. Select all
and copy the image (ctrl+a to select
all and ctrl+c to copy) make a new Alpha
channel in the Difuse Render and paste
it in there.
Now
copy the alpha channel of the Shadow
render and just as the Z Depth make
a new alpha channel and paste it in
there, so now what you got is a Difuse
Render with 2 Alpha channels.
3DTotal
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What
we need to do now is symply, load the
shadow selection, (ctrl+left click)
and make a new layer and paint it with
black. Give it a opacity of 30 (just
hit 3 in your num pad) I use a soft
light as blending mode, you can use
normal or any other or even paint your
shadows any color you want and make
any color correction you need (usualy
I just use color balance).
If
you are happy with the results...well
flatten your image and got to Filters>Blur>Lens
Blur and there use your alpha channel
2 (Z Depth) to blur your image, use
any values that you think are ok, but
always have in mind the the Blur Focal
distance means the gray color that your
focus object is, so if yor object apears
to be gray, check the values of the
gray (i.e R128 G128 B128) and use it
in here:
This
the real thing, you can add the DOF
as needed more or less depending of
your needs, also adding noise if you
want (I realy like noise in blured images,
and the best thing here is that you
can see the results in real time if
you use the faster mode and then apply
it in More Acurate mode).
Now
the final Result in a fraction of the
time that should take it render the
whole thing in Brazil rs, at the end
I render also the self ilumination channel
to add a glow in the blue areas.
I
hope this was usefull...The render times
where 9:52 min for the Brazil render
pass and 16.56 min for the Default Scanline
Render (shadow and Z Depth) I should
say that I start a new render with Brazil
using the same values for AA but added
DOF and area shadows and has pass more
than 25 minutes and the Brazil hasnt
render any bucket (64x64) so this demostrates
that this way is a lot easyer and faster.