2D compositing in vegas with a 32 bit alpha channel image with PhotoShop tip
0how to work the time line, the books never show this.
note:
my favorite vegas layout, used at 1920 x 1080 or 1366 x 768 .
I never need a really long time line, but instead,
more tracks vertically to composite with.
sony vegas compositing for 5 6 7 8 9 10 11 12 it's all the same.
screen caps were done at 1920 x 1080 *.png ,
with a program I wrote in c++ .
uploaded as wmv7 1920 x 1080 no audio
note the "trap" when I first select "multiply" for track 11 ,
the video viewer monitor goes blank, because track 11 is being
multiplied by nothing below. with a large composite we need
to know how tracks will interact other wise we may adjust a
track and see no change in the video viewer and wonder if vegas
is working properly, yeah it most likely is, so we then just messed
up our settings. ie; if I should adjust track 11 right now, we will see
nothing happen, until we drop content onto track 12 . That's when
we will see what a mess we made of track 11 .
The planet image is a png 32 bit with 4 channels
Red Green Blue Alpha , each channel is 8 bits.
photoshop elements can make an alpha channel
image if you save it as png 32 bit, AND you
do NOT paint the entire background .
So, you must see at least some checker board
background( transparency ) in photoshop in order to save with
an alpha channel.
In photoshop, always choose to see the transparency
checker board, then you know If you have painted
on the entire image.
If your source image fills the entire work space
and you save as png 32 bit, you still get
an alpha, well, it will be ALL white. Erase some
of it first, to see some of the checker board,
now save as above.
rest of PhotoShop tip
start a new blank project in PS , all you should see is a checkerboard( transparency ) as no pixels have been painted yet.
The alpha channel for this image will be all logical 0( 00 byte , black) to start with.
paint 1 pixel and PS will also Tag the corresponding byte in the alpha channel
with a logical 1( 255 byte , white )
So, paint a Red square in the middle( surrounded by that checker board )
We already know the alpha channel will be a white square in the middle
surrounded by black. Render out to 32 bit PNG . Import into vegas,
give vegas access to the alpha channel as imported, then use Mask Generator
and tell vegas to USE the alpha channel, and sure enough, we have our mask,
the 8 bit alpha channel.
NOTE: we could choose to use the R G or B channel
as a mask too. I have a tutorial for that as well. A channel is a channel .
The alpha channel, by default, is always viewed as black and white .
A common technique is to pack 4 mask images, one each, into the RGBA channels.
Now, one png 32 bit image holds 4 masks. PS can build it too.
Do I have to make a special 32 bit image to use an
alpha channel effect ? No , External black and white images
can be used too, but if you can build it as 32 bit with alpha
"built in" you only have one image to work with, simpler to use.
Plus the alpha image will be customized to the RGB part
as viewed in photoshop, to get the perfect "cut" , later on.
vegas can render video as 32 bit avi uncompressed with alpha channel .
this tutorial lays the ground work for the remaining tutorials on maskng.
you can manually make a black and white image and use that as the mask .
The basic vegas mask tutorials provided by Sony
use this "extra image" kind of mask.
With Sonys' tutorial, no alpha channel will be used because you are
providing an explicit discrete black and white image\mask,
then all remaing techniques of my tutorial should\can be used.
technically, for this tutorial,....
track 11 combines with track 12 using track 11's blend mode "Multiply"
and 12 is( indented ) made a child of 11 , ie; 12 is a parent of 11
then,
track 13 combines with track 14
finally,
the entity of tracks ( 12 11 )
combines with
the entity of tracks ( 13 14 ) ,
using the "Parent blend mode" of track 11 ,
Parent Blend Mode is at the far lower left of track 11s' "track controller"
The "Composite Flow Diagram" is part of Sony Vegas documentation
I added my own notes to the picture because Sony does not go into
any detail about it.
When I get to it, I will upload an animated\dynamic mist,
covered planet tutorial. Great for making fog for any occasion
( I did, see Red Mist Planet and misty fog ).
I did the 3D compositing tutorial of that thumb nail shown,
ring around the planet . Yeah, that is a 3D'er .
The ring around the planet is a 3D composite of a vegas Generated Media .
The yellow track has been rotated in 3D , on the Z axis .
still, mostly, these tutorials are about how to work the vegas time line to composite.
It can be tricky. It certainly gave me plenty of head aches, ouch !