[Duca Simone luchini]

No, no, of course, i have before over the clip putted but.

I but I just read that maybe this is a bug in Pre Pro CS6 …
I’ve 6.0.2 Mac os but Adobe has not still fixed this bug. That’s really bad…

[Duca Simone luchini]

Hallo everybody,
I make two different simple freeze frame in .TGA (premulty matte) to have transparency and to composite both in Premiere Pro over a Background clip.
(I also tried with PNG (premulty matte)
In AE I have this Diffuse Pass:

and this Shadows Pass:

When I import in Premiere Pro, I interpret both .TGA and I check that any “Ignore transparency” is unchecked:

All right, but why I still can’t see transparency (Alpha is black…!)?

[Duca Simone luchini]

Wait, wait, : you’re saying that when I import a premulti 3d obj and interpet it as a Premultiplied footage, AE automatically dales alpha channel leaving tham as premulti when I composite (R*Alpha, G*Alpha, B*Alpha) , and trasforms them in a unpremultiplied (R,G,B) when I’m going to grading?

Is it right?

Many thanks!

[Duca Simone luchini]

Hi Todd,
can you please explain better what you mean when you say: “The color matting is removed to interpret the alpha channel when you import the footage”?

If we are agree that the basic compositing formula is
Foreground * Alpha + Background * (1- Alpha)
that means we have ALWAYS premultiply Foreground (3d object):

Foreground R * Alpha
Foreground G * Alpha
Foreground B * Alpha

to make a right compositing.
When we import in AE a premulty 3d object to composite it, I don’t know exactly what happen automatically but if you interpret this footage you ‘ll see that AE say you that it is premulty.
So you can make a right compositing. But when you have composited, you have to turn this 3d object in Straight to have the right (pure) R G B channel to make Color Correction, cause now, you have still a R*alpha, G*alpha, B*alpha color channel…
Just now, at this step I don’t know how to dale my 3d object (still premulty):
maybe I have to duplicate it and interpret as Straight and make a match between Bg and this Straight 3d obj.
But I’ve composed with a 3d premulty object and I don’t know at end how to unify compositing 3d (with premulty 3d object) and Grading with (With straight 3d object). That’s my problem.

[Duca Simone luchini]

Good Ross, very clear!
Many thanks!

[Duca Simone luchini]

Wow Ross, your explanation was very good!

If I’ve correctly Understand, we have to use specific 3d tacking sw when we have to rebuilt an entire geometry scene in a shoot with deep focus and many objects (people. f.i.) or geometries (Buildings, houses. mountains… f.i.). In a shot with soft focus, just with an object (in focus) and a defocus Background, you are not interest ti build a 3D Environment but just to place moving plans in synchronism with the original camera movement.
If have I understand…

[Duca Simone luchini]

Hi Ross,
Very interesting this post above all for the improvements about Mocha concerning 3D tracking!
But when and why is better to use a 3d sw tracking, instead Mocha, as Syntheyes, Boujou, Matchmover and many others?

Thank you!

[Duca Simone luchini]

Hi Ted,
Thanks, but I think we need a… tutorial.
Anyway I’m going to try to make it in a 3d software… I’ll say you if and how does it works.
many thanks!

[Duca Simone luchini]

Hi, Ted, I wrote you also in this post:
https://forums.creativecow.net/thread/2/1029873#1030476

My problem, shortly, is to understand what do you mean when you say ” …and then drawing them in psd is the way to go”.
Help… please!

[Duca Simone luchini]

Hi Ted,
I tried to make surfer displacement map in Photoshop but I can’t make something as you’ve done. I duplicated surfer selection and applied Hue (Saturation effect to make selection in grey scale. But you displacement map was something like a Z depth maps… and not a B&W image. I really ask help ti make the same mask as you have done in your tut. Many thanks!