Matte question

[pixeldaddy]

Hi !

Being new to compositing and DF, i have one question on how to use premade mattes in Fusion ?

By premade mattes i mean eg stock footage that come with both a color sequence and a matte sequence. Or if i use a lumakey to generate a matte and use that to key with..

I've looked around for checkboxes, read helpfiles, looked for nodes that are designated alphanodes.. but i find nothing..

Maybe this is so basic that it applies without saying.. if so I might be the most dense person in the universe.. Enlighten me please!!

I've figured it might have to do with channel booleans.. if i'm on the right track, could someone please push me in the right direction and spell it out for me ?

http://www.home.no/ottothorbo/matte.jpg



Thx,
Otto Thorbo

:stupid:

[Hugh]

If you've got both your sequence and matte as seperate files, you need to bring them both in via a loader.

Then add a Mask to your sequence loader, and make it a Bitmap Mask. Drag your matte loader into the box that asks for a node to use as the mask.

I think this will work - I don't have Fusion in front of me at the moment. If this doesn't work, then add your two loaders as I described above, and also add a background (black with alpha set to 0) - add a merge with the black as the background and the sequence as the foreground. Add a bitmap mask as I described to the Merge node. I know this second method will work, but the first one (if it works) will be cleaner....


Reading more of your post (I really should have done that first...) yes, Channel Booleans will do this for you too.... Pipe your sequence into the background input and the matte into the foreground. in the Channel Booleans node, set the output R, G and B to be the background R, G and B, and set the output Alpha to be the foreground Alpha...

[SalaTar]

Here ya go flow and immages attached in zip

[jayk2k]

Hugh's method will work, (if you use the red, green or blue channels, not the alpha) but a slightly more correct way would be to use a matte control node.

LD RGB------->Matte
^
LD Alpha----------|

Set the matte tool to copy and combine red, green, or blue (all should be equal values in a b&w matte).

Hope that make sense..

[Hugh]

Of course.... now I feel stupid....

I've never used Fusion with CG footage - so any mattes I've used have either been keys that I've pulled in fusion or masks that I've created...

[SalaTar]

Jay,
Is this more correct, or did I miss?

[jayk2k]

Don't get me wrong guys, part of the power of DF is the flexibility it offers in these types of instances..

I just find the physical connection is easier to "read" in the flow, and offers the added functionality of matte blur, clipping, expand/contract etc, all in one node over the channel boolean option.

SalaTar: Yeah, this is more my example. I didn't download the footage, but the settings under the matte tool seem a little out of whack. (expand/contract is ok, but a matte gamma of 3 seems a tad extreme)

[SalaTar]

I was using the jpeg in post to make a tga .lol

[pixeldaddy]

Gentlemen, you have brought peace and tranquility back in my life. Thank you for your quick replies, and for proving that there are more than one way to work round a problem.

Cheers,

Otto Thorbo

[Hugh]

I quote "Programming Perl" (The Camel Book): "TMTOWTDI (There's More Than One Way To Do It)"