Search results matching tag 'compositing'

BCC Chroma Keying Workflow in Avid Media Composer

Johnla — Sat, 13 Jun 2009 01:11:09 GMT

Achieving a convincing chroma key composite is more than just slapping in a background and keying a foreground. It requires the use of integration techniques to marry the image elements together to give the impression they were shot with the same camera at the same time. This five-part tutorial demonstrates how to build a chroma key composite using Boris Continuum Complete (BCC) AVX plug-ins inside Avid Media Composer. Compositing tips will be shared and you will see just how easy it is to nest and pass a matte to multiple BCC effects in your segment. The end result will be a seamless composite.

Filters covered:

• BCC Chroma Key
• BCC Matte Choker
• BCC HSL (Hue-Saturation-Lightness)
• BCC Lightwrap

Click the videos below to play the tutorial. A full text transcription is included below each video.

Part 1:

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Clips

First, let’s take a look at our clips. Our foreground is a toddler in a frog suit. He is in our V2 track. We’ll be compositing him over a tiled wall background in the V1 track.

Let’s begin by going to the Effect Palette. Inside the BCC Keys and Matte category we’ll drag the BCC Chroma Key icon to the foreground track of our multi-layer segment in the timeline.

Enter Effect Mode

Notice the foreground is already keyed - that was easy wasn’t it? That’s because our key color is set to blue at default. That’s okay, but we want to be more precise than that. So, we’ll sample our blue from the bluescreen.

Pulling the Key

The first thing we want to do, is click the Bypass button, which is located at the top of the Effect Editor controls. This will turn off the effect so we can see our bluescreen again.

To sample the color, let’s go down to the Color control, which contains a color palette and an eyedropper tool. Hover over the color swatch until it turns into an eyedropper, grab it, and drag it up to the Effect Preview Monitor. We're going to sample the blue closest to the boy's hairline - since the face will be the focal point, we want that area to be keyed well.

We’ll go back to our controls and click Bypass again, and there is our composite in progress. In case you’re curious and you want to view the matte we just created, set the output to Show Matte. This will help you see any problems in the matte that you may have missed when in Output Composite mode. You can see that the white foreground is opaque and the black background is transparent, which means we’ve pulled a pretty good key. If that isn't the case with your key, BCC Chroma Key offers several tools to help you clean up, adjust, and nail that perfect key. Those parameters are explained in detail in the BCC Chroma Key help document, which can be launched by pressing the Filter Help button near the top of the Effect Controls. By the way, all BCC filters contain their own help docs, which can be accessed by pressing that button.

Part 2:

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Spill Removal

Now that we keyed our foreground and established a pretty good matte, the next thing we want to do is remove any blue spill that might be reflecting from the blue backing onto our foreground subject. Change the output menu back to composite.

Why don’t we zoom in a little bit here so we can get a closer look at our toddler. You can see some blue spill on the edges of the frog suit. Now, we can reduce that spill by lowering the Spill Ratio control, which is located in the Spill Suppression group. It’s important to make small adjustments here though, as you may end up turning your foreground subject yellow.

Here’s a tip when correcting blue spill on people – always look at the face. If they are looking a bit jaundiced as a result of a previous adjustment, take the Tone Mix control down a little bit to bring back a healthier looking flesh tone to your subject.

Fixing a Problem Matte

Most often the case, you’ll have a first-pass matte that has unwanted holes in areas that should be opaque. Adjusting parameters like the Density control in BCC Chroma Key can help fix that, but doing so, can also “fatten” the matte resulting in a degraded edge or Matte Line around your foreground. To fix this problem, we’re going to add a BCC Matte Choker filter.

Before we add the Matte Choker effect, let's untwirl the Title Matte parameter group in the BCC Chroma Key controls and select Multifilter Start. You'll notice the bluescreen suddenly appear - that is normal. This action will allow us to nest this segment and add more filters.

Inside the Effect Palette, navigate to the BCC Keys and Matte category and Alt-drag the BCC Matte Choker filter and drop it on the foreground track.

Now, let's untwirl the Title Matte parameter group inside the Matte Choker controls and select Multifilter End. We now have a BCC nested effect.

Inside the Nest

Here is a diagram that shows our BCC Nest within our segment. Our background tile wall is here in the V1 track, and our foreground toddler is in the V2 track. Also in the V2 track, are the BCC Effects we’ve applied so far: Chroma Key and Matte Choker. Since we only have two effects right now, Avid assumes it is a first and last effect. That is why we set our filters to Multifilter Start and Multifilter End. As we add more filters to the nest, those settings will need to change, as I’ll explain later.

Getting back to our matte problem that we’re going to try to fix with BCC Matte Choker.
At default, it looks like the values are doing their job a little bit too well. So, let’s lower the Blur 1 control, and Choke 1 control slightly, and that should give us a nice looking edge with no matte line.

Part 3:

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Color Balancing

The next aspect of our composite to think about - is color. Does the foreground fit into the background colorwise? Almost. So, we need to add another filter.

Before we do that, let’s go to the BCC Matte Choker controls in the Title Matte parameter group and select the Multifilter Mid checkbox. Once you select Multifilter Mid, the image no longer displays composited over the background. For this reason, while you adjust your middle filters, it helps to select the Multifilter End checkbox so you can see the result as it should be seen. Then when you're finished adjusting, select Multifilter Mid again and your nest is ready for a new filter.

Inside the Effect Palette, if you navigate to the BCC Colors and Blurs category, you’ll see a bunch of color filters available at our disposal. Each one has their place, but the one that will best serve us right now will be the BCC Hue-Saturation-Lightness, or HSL effect. Alt-drag that filter onto our foreground V2 track.

Whenever we do color balancing, it’s always a good idea to see the foreground composited over the background because that’s what we’re color matching to. So, let’s go to the Effect Editor, inside the Title Matte parameter group and set Multifilter to End so we can see it over the background.

Whoa. That frog suit just jumps off that background; so, we should desaturate it a bit. Let’s go to the Saturation control and lower that. That looks better. Always remember to look at the flesh tones, and our toddler is looking a little magenta, so we’ll shift the Hue on him a bit. There we go.

Part 4:

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Making it Seamless

Next, we're going to add one of my favorite BCC effects, the BCC Light Wrap filter. I really like this effect because it adds to the realism of a composite by creating an edge matte that allows the background image to be reflected around the border of the foreground image – and this results in a very seamless composite.

As always, before adding a new filter, we need to go into the existing filter and inside the Title Matte parameter group, select Multifilter Mid. Now we’re ready to add BCC Light Wrap. So, let’s go to the Effect Palette, inside the Keys and Matte category, and Alt-drag the BCC Light Wrap filter and drop it on the foreground V2 track.

Inside the Effect Editor, let’s untwirl the Title Matte parameter group of the Light Wrap controls and select Multifilter End. Since this is the last filter we’re going to use in our nest, we can just keep it set to End.

How does all that look inside our nest? From the bottom of the nest, we can see the first effect we applied – BCC Chroma Key. Then on top of that, we stacked our middle filters – BCC Matte Choker and BCC HSL, both set to Multifilter Mid. And, the icing on the cake, our last filter, is BCC Light Wrap set to Multifilter End.

Getting back to the Light Wrap effect, it should be working right at default. To see that, let’s change the View menu to Wrap On Black and you’ll see the edge matte that was just created.

Let's change the view back to Normal and go back to the controls. I'm going to back off a bit on the wrap effect because the hands are looking a little muddied. Go to the Width control and bring that value down slightly while we watch the hands.

Change the View back to Wrap On Black, we have less of an effect applied, we can see it right there, and then we’ll change the view back to Normal.

Part 5:

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A Last Detail

For a final touch we’re going to add a drop shadow to our toddler. We could use the BCC Drop Shadow filter located inside the BCC Effects category, but why would we? All of the BCC keying and matte filters contain drop shadow capability that conveniently allows us to add a shadow effect during any of our matte-key processes. So, with that in mind, lets go to the Effect Editor and scroll down to the bottom of the BCC Light Wrap controls where we’ll see a Drop Shadow parameter group. Untwirl it and select Enable Drop Shadow. Right out of the box the drop shadow looks pretty good, so no need for adjustment.

And, there’s our composite showing all of the nested effects applied. We achieved our goal of getting the foreground to fit into that background environment. But don’t stop here! Feel free to experiment and add more BCC filters to your nest. For example, if your blue or green screen was shot using a Red One HD camera, but your background was shot on 35 millimeter film, add a BCC Match Grain filter to your nest to add grain to your clean Red footage.

That’s just one of many solutions BCC can offer you, the Avid Editor. This has been John Lafauce for Avid Technology.

BCC filters come bundled with Avid Media Composer, Avid Newscutter and Avid Symphony.

Too many composites

flicmaker — Sun, 31 May 2009 17:33:49 GMT

Hi All! I am working on a sci-fi short with a lot of green screen shots and wanted to get advice from cutters with more experience.

I find that I have so many layers of compositing in my timeline that it really slows down my working speed. Just to cut together two shots seems to take for ever because I have to build the two shots first. Then there's the rendering...Oy!

I have avoided using video mixdowns as much as I can, because they don't translate when it comes time to online.

So my question is two fold:

First, how much temp compositing do you guys bother to do during offline, when you know all the effects are being redone, outside of Avid, for the online?

and Second, is there a way, other than video mixdown, to have a single segment in the timeline, refer to a seperate sequence. (FCP has this ability, allthough I don't know if it translates to EDL or into the online.)

Thanks in advance for your advice!

flicmaker

Introducing Particle Illusion

drbgaijin — Thu, 02 Apr 2009 08:25:38 GMT

About 2 years ago, when I was still using Avid Liquid, I was having such a tough time climbing the learning paths to Boris FX and Boris Grafitti (I had bought them as alternatives to the more expensive After Effects) that I searched for a cheaper easier to learn compositing programme.
I needed to make a volcano errupt!

After a lot of searching I found Particle Illusion.
Last week I read on Creative Cow's website that the relatively unknown Particle Illusion was to be exhibited at NAB 2009.
So, I felt that this tutorial might be of extra interest to anyone looking for a compositing programme with an easy learning slope....

The article on Creative Cow's forum is to be found HERE!

AE is still out of reach for me, but I find that Avid FX is more than enough for the simple effects I need in my editing style and needs
With the exception of errupting volcanoes!.

Good luck and Regards,
Douglas

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This tutorial can be viewed at "Full-screen" by clicking on the icon on the toolbar

How to add and adjust an effect on a keyed foreground (e.g. SpectraMatte) without affecting the background

Johnla — Fri, 16 Jan 2009 20:11:12 GMT

Avid processes effects using a track hierarchy - anything on a higher track effects the tracks below. Below are two methods to add effects to foreground (higher track) elements without affecting the background (lower track) elements in Avid.

Method 1: Using Avid Filter Effects

In this example, we are dealing with a SpectraMatte keyed foreground element that needs to be Color Corrected while the background element remains unaffected.

- V1 is the background.

- V2 is the foreground to be keyed. Drag an Avid SpectraMatte or Chroma Key onto it and create the key as desired.

- Step into the segment effect by clicking the "Step In" arrow button on the bottom of the Timeline window. Click once since there is only one effect (SpectraMatte) applied. There should now be an "N1" appearing in the Timecode button (see "Stepping Into and Out of Nested Effects" in the Avid Help for more information).

- Drag an Avid color filter (e.g. "Color Effect" from the Image category) onto the foreground V2 track.

- To adjust the color controls while viewing the foreground over the background, step out of the effect by clicking the "Step Out" arrow button. This will display the full composited sequence.

- To access the color controls, enter Effect mode and double-click the nested effect (V2 track). This expands the nested tracks above the effected clip in the timeline.

- Select the track (e.g. it will be called 1.2) containing the color effect and adjust the controls in the Effect Editor as desired.

- When you are finished, collapse the nested effect by double-clicking the foreground V2 track.

Method 2: Using BCC Filter Plug-ins

In this example, we are dealing with a BCC Chroma Keyed foreground element that needs to be Color Corrected while the background element remains unaffected.

- V1 is your background.

- V2 is your foreground to be keyed. Drag a BCC Chroma Key filter onto it and create your key as desired.

- Set the BCC Chroma Key Multifilter control to "Multifilter Start".

- Add a Boris color filter (e.g. BCC HSL) by Alt-Dragging it onto V2 to nest it.

- Set the BCC HSL Multifilter control to "Multifilter End" and make your color adjustments.

Post by Kate Ketcham, Customer Support Supervisor/Avid Certified Instructor

and John Lafauce, Customer Support Representative

Avid DS Motion Parallax (3D)

Igor Ridanovic — Sun, 11 Jan 2009 23:29:53 GMT

This tutorial explains the use of custom Motion Parallax preset for Avid DS V10.
The plugin adds 3D capabilities to the DS compositing environment. To download the plugin visit
HDhead.com.

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Animatte

TrainerDave — Tue, 11 Nov 2008 03:12:41 GMT

In this episode, we use the Animatte effect to create an isolation so a colour effect can be applied to only a part of the scene

http://community.avid.com/forums/p/65284/365707.aspx#365707

Avid DS Composite Containers

Igor Ridanovic — Sun, 19 Oct 2008 23:33:40 GMT

Learn how to create composite containers in Avid DS. Composite containers can collapse multiple tracks into a single clip and also allow you to use the powerful compositing features in Avid DS.

Download Avid DS presets from this and other tutorials.

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Re: What are your favorite techniques?

Johnla — Tue, 14 Oct 2008 18:27:15 GMT

Have you tried the tutorials on the Boris site?

http://www.borisfx.com/tutorials/#null

They have some for BCC AVX as well as for other hosts.

Here's another resource:

http://library.creativecow.net/search.php?q=avid+fx

Just curious, I've read similiar complaints regarding effects in Avid. Do you feel there isn't enough tips and techniques out there? If you feel that way, would you like to see more demos and tutorials (Avid FX, BCC, other 3rd party)? Real-world applications? Compositing and motion graphics techniques?

Future stereo3D viewing should also support RightEye on top (KMQ viewer)

Thomas Kumlehn — Thu, 08 May 2008 16:29:25 GMT

Future stereo over/under viewing should also support RightEye on top, because I would like to use the openKMQ prism glasses with a simple fixed distant mount to avoid using expensive stereo enabled displays or beamers.

A plus would be to extend the view to two LCD screens - for full res, full colour, full brightness previewing with these glasses. That's probaly easy because you might already support dual DVI output for stereo beamer projection.

Re: Real Newbie.

mhollis — Thu, 27 Mar 2008 18:21:05 GMT

You might also look at my response here in the forum to another new user. I do recommend taking all three classes and then also working with someone who is experienced, or hiring someone who knows the DS for a time while you get your feet wet.