Why can't I get Bezier Mask to work?

[Paul Cascio]

I copy the track and set the Alpha on the upper track to Straight. Then, I outline the subject, but nothing happens. Am I missing a step somewhere? Should the bottom track have Alpha set?

Thanks

[Andrew Kufahl]

Hi Paul,

Not sure I understand your terminology... What is the "Alpha" you are referring to? The only thing I can think of is that you are talking about the compositing mode. And where do you see a "Straight" option? (There is no "straight" compositing mode.)

Can you describe what you are trying to accomplish? It might be easier to help if we understand what you are trying to do.

Andrew

[Paul Cascio]

Sorry...I set the Alpha Channel properties of the upper clip to Straight.

I'm trying to update a talking head video I produced. I learned later that I was too close to the background, so I want to mask out the talent's head so I can darken and blur the background.

[Andrew Kufahl]

Personally I haven't used the "Alpha Channel" in vegas. But, it doesn't sound to me like it does what you are thinking it does. I could be wrong, and hopefully someone will say so if I am... but I don't believe your video really has an alpha channel in it.

Here's what I'm thinking you'd want to try...

- You have a track with your source video on it.
- Duplicate that track.
- On the upper track, open the video event's pan/crop.
- Click the checkbox in the keyframe area to enable a mask.
- Use the anchor creation tool to draw your mask around the subject.
- Set the "feather" settings according to what look you want.
- Close the pan/crop window.
- Now go to the lower track and add an event FX to the video event (such as guassian blur), and adjust accordingly.

The problem with this technique though, is that you'll need to adjust your mask [position] whenever your subject moves... depending on how much movement there is, and how long your video is, this could be quite a chore.

I believe there is a Vegas tutorial out there for doing exactly what you are trying to do. However, for it to work properly you would have had to capture footage of the scene without your subject in the way. It's sort of an ad-hoc green-screen method without actually using green-screen.

I hope some of this helps,
Andrew

[Paul Cascio]

Thanks Andrew. I just realized that I've been adding the FX to the wrong track. It should be added to the bottom track.

Thanks

[Jason Robinson]

Originally Posted by Andrew Kufahl

Personally I haven't used the "Alpha Channel" in vegas. But, it doesn't sound to me like it does what you are thinking it does. I could be wrong, and hopefully someone will say so if I am... but I don't believe your video really has an alpha channel in it.

Here's what I'm thinking you'd want to try...

- You have a track with your source video on it.
- Duplicate that track.
- On the upper track, open the video event's pan/crop.
- Click the checkbox in the keyframe area to enable a mask.
- Use the anchor creation tool to draw your mask around the subject.
- Set the "feather" settings according to what look you want.
- Close the pan/crop window.
- Now go to the lower track and add an event FX to the video event (such as guassian blur), and adjust accordingly.

The problem with this technique though, is that you'll need to adjust your mask [position] whenever your subject moves... depending on how much movement there is, and how long your video is, this could be quite a chore.

I believe there is a Vegas tutorial out there for doing exactly what you are trying to do. However, for it to work properly you would have had to capture footage of the scene without your subject in the way. It's sort of an ad-hoc green-screen method without actually using green-screen.

I hope some of this helps,
Andrew

All you need is one or two clean frames and then apply the velocity envelope to that frame and freeze it at 0% playback speed and apply your blur effects to that background. Of course this means you still need to key frame that mask on the top track.