Premultiplcation Problem?
by ouzelum
on
Oct 9, 2006 at 5:01:03 pm
I'm a new user and am running into some issues that are probably an easy fix. I'm attempting to separate a person from the background of a normal clip (there is no green screen, etc). They are wearing dark clothes so I have a rotoshape as a garbage matte for the filein node and the clip outputs to a lumakey set up to further isolate them. The problem is that I need the garbage matte to apply to the lumakey as well, but when I patch the rotoshape to matte both the filein node and the lumakey, there's a halo around the garbage matte (I'm assuming this is a premultiplication issue). What is the proper way to cascade multiple nodes so that they act as one mask?
thanks.
Re: Premultiplcation Problem? by CaptainMench on Oct 11, 2006 at 12:43:31 am
Kind of hard for me to see EVERYTHING you are trying to do...
BUT --
A few things to keep in mind.
If you can avoid touching your FileIn node with any kind of mask you'll be better off for it.
Depending on where it is, I like using an IAdd node for adding Rotoshapes. Pull the noodle in from the source branch (sometimes when it's below the key -- the key branch) onto the left button (input) then create a new shape and use the left green button from the FileIn node and the RIGHT green button from the shape node and draw your shape. Then add it to the left side of the IAdd node. Then, pretend THAT's your fileIn.
Another place to avoid using masks is in the mask side button of a keyer node. Big no-no.
There's a way to post the text of your script here... but I always forget - plus, I've got a nice Cab infront of me at the moment... so I shouldn't be looking into any files I can destroy at the moment...
