Properly Setting up a Track

As I become increasingly frustrated with a poorly executed screen track that I am working on as one of my products, I've begun to think about the best way to set up a track on set so that it minimizes the effort required in post.

I found this neat little article that talks about the best way to go about marking the set so that you can get an easier track in post. https://www.fxguide.com/featured/art_of_tracking_part_2_tips_and_apps_overview/

SPACE JAM

One of my all time favorite movies, and one that interestingly I hadn't thought to take a look into. Until one of the film blogs I follow (www.traslacamara.com) posted an interesting article on the actual BTS. This was super relevant because we had just done the tracking lab in class and I can only imagine all the tracking that went into this movie.

As you can see they used many actors dressed up in morph suits to get the motion down, but interestingly enough I didn't see any track points on the actors themselves, which must have made putting the animated characters over top of them a bit of a struggle.

And if that wasn't enough to satisfy your BTS needs, here is a fantastic video of them actually shooting (A+ camera movement as well)

2D Motion Tracking Tips

The 2D Tracker

In After Effects, there is a standard tracker that will track parts of a video clip. See the image below. Basically, Box A looks for what ever pattern is in Box B across every frame, then exports this movement to the crosshair C.
Box A is call the Search Area
Box B is the Pattern Area
and the Crosshair C is where the data is exported to.

Once you hit play, After Effects follows the Pattern Area by scanning through the search area for the same pattern every frame.

That's all fine and dandy when you pick good tracking points, but what makes a good tracking point and how does this tracker work?

Good Tracking Points

For the most part, you want to select points with high contrast. This is all well and good, but what if you can't find any? as it turns out there are a few solutions:

Only track points that actually exist

Don't try to track the intersections of two objects because no mater what you try, that point is not going to stay the same as the camera's perspective changes. 

Don't track the edges of objects

Often there is high contrast on images with a building and the sky, but if this was a vide, we do't want to track that edge. For the most part, these edges allow the tracker to slide across it because of the similarity in the texture of the building and the texture of the sky. This results in an inaccurate track.

Never take your eyes off the track

When the computer is tracking your point, don't let yourself become distracted. Often when you aren't watching it, the track will veer off target. By watching it, zoomed in, you will know how accurate this track is going to be before it even finishes.

Use the right size tracker

As in most Tracking programs, you can designate the size of the pattern area, and the search area for your tracker in after effects. By changing the size to only encompass what you're trying to track you have a better chance of catching it every frame. Also if there is a lot of motion in your frame, perhaps it makes sense to have a larger search area.

What points to avoid

When tracking your points of high contrast make sure to pick points that do not have:

• Motion Blur
• Soft Focus/Rack Focus
• Occlusion
• Noise
• Low Contrast
• no features /single color
• Interlacing

Some Ways of Correcting the above issues

Motion Blur

Expand the search area. The extreme motion of the camera maybe causing the pattern you were trying to track the movie on the default search area and this will cause a tiger to stop or slip.
Expand the pattern size. This gives this offer more information to work with and might help it to continue through the motion blur.
Sometimes manually tracking the point at the parts where the clip is most blurry can keep it on track.

Soft Focus/Rack Focus

Use a bigger pattern size. Bigger pattern sizes can sometimes compensate for the noise in the soft focus features because the program is simply more pixels. This causes a sort of averaging effect on the track.
Slightly blurry the image. It seems to go against common sense to blur the plate when blurriness is the problem you're trying to solve. This technique sometimes is more effective because it will help get rid of the graininess and produce a smoother track.
Sometimes tracking from the in focus part of the shot to the out-of-focus part gives you a better result too.

Occlusion

In order to solve occlusion, you can track it by hand or for the frames your tracking point is occluded find another tracking point that could potentially work for a little while. Make sure, when you move the pattern and the search area, that you leave the origin (Crosshair C) right where it was. It should still follow the motion, relative to the position of the pattern and search area.

Noise

Whatever you do, try to remove the noise. Noise really confuses it to the tracking system. If even buy D noising your image, you still have a lot of green, try tracking only one channel.All video is composed of R G and B values, and perhaps there is less grain in one  or two of those three channels.If all else fails's, do the track on the noisy shot, and use the smoother to all on the keyframes.

Low Contrast

Most 2D trackers will use the luminance value of the pixels they are tracking. If you can try tracking only in our, G, or be color channel instead. Sometimes one of these channels has more contrast than the others.Another solution is to add an effect of the clip that makes features more "legible." If you add a sharpen effects to your clip perhaps you can get better results.

no features /single color

If your clip has almost no features and is more or less a single color there is not many options. You could try tracking an edge, but the tracker may slip. You can try playing with the color channel your tracking, but you may not get any more information there either. Ultimately if you have to track a shot like this you are better off tracking it manually.

Interlacing

The easiest way to deal with this problem, is to Deinterlace the image before you begin your tutti track. Most compositing programs have a Deinterlacer.


I hope that you found some of these tips helpful in the projects you're working on, I know that they have been helpful for me and my green screening project!! 

Tracking in Mocha with Mary Poplin

So for my green screen project, I have a few shots where I need to use tracking in order to sell the effect that I am trying to pull off. But for some reason I've been getting very strange results when I track in Mocha. Some of the tracking ends up looking a bit jittery, which wont translate very well when trying to pull of my visual effects.

I've recently been watching videos about using mocha and how to get the best results with difficult shots. I've found that if you want to learn more about mocha tracking, a good resource is from someone who actually works for Imagineers Systems (creators of mocha): Mary Poplin.

Mary is a pro VFX artist/tracker/roto painter. I've watched 2 videos so far where she goes through how to get a good track in Mocha to get good clean results in order to roto paint onto a clip of a couple short films. I found her through the Film Riot community because she has worked with them on 2 short films both of which involve rotoscoping and painting things out of shots by using Mocha. She does go through the shots pretty quickly in her tutorials, but You can still learn a lot from her.

So now I'm going to see how I can use what I learned from her and apply it to my tracking in my green screen project and see if I can get any better results then before.

If you want to check 2 of her videos, they post right below:

Let's Track A Bit... Shall We?

So while I was scrolling through some videos on YouTube, I came across this video that I right away knew had After Effects editing put in on it. They had used the tracking effect in order to have each of the cartoon body parts (ears, eyes, hats, etc). It's actually really cool to see this done because, well for starters, I knew all of the cartoons that the band was playing, but Just to see it tracked so well and have some of the other ones animated while being tracked was cool too.

One of the really cool effects that was used was the music notes that came out of the instruments and hands as the players hit certain notes or hit certain keys on the piano or certain areas on the percussion sets. I loved this video and I thought that it was really cool. I would love to be able to do something like this when I get more advanced on After Effects. It would make for a great video in my reel and it would also just be plain fun to do something like this to one of my favorite songs.

It Just Feels Good At First

Train came out with their new music video for their song "Feels Good At First".  This music video features a very cool effect where you watch the video in a silhouette of Pat's head.  As well as this, the music video plays a lot with transparency to help create the idea of reminiscing on memories.

If I had to guess how they created the effect of playing the music video in the silhouette of Pat's head, I would say that they masked his head and took out Pat's face.  They then inserted the music video into where Pat's head was.  But if you look closely, there is the rest of the image in Pat's head on the outside of the silhouette, just with a higher opacity.  This could be done through using Mocha to track and then mask Pat's head.  It's a simple technique with a creative and powerful image.

Leap Motion

This technology is very cool.  Supposedly it is 100 time more accurate than “Kinect” for Microsoft's game system, Xbox.  With this new technology, there is a system of cameras, sensors, and inferred light emitting diodes that all interact to make this possible.  Also unlike other existing systems, such as “Kinect,” Leap Motion can track up to ten fingers all at once in a three-dimensional area of about eight cubic feet!  The largest difference between this technology and others, is that this device is placed below that tracking area, whereas many others are placed in front of it, looking straight on.  It is compatible with Apple and PC and just plugs into the computer.  There are also countless applications for the technology including gaming, modeling and numerous others.  The product will me available in the market on May 13th, which makes things all the better!

The 2011 Oscars and how it relates to our next project

In the spirit of our latest project assignment, I recalled the opening to the 2011 Academy Awards. The show was hosted by Anne Hathaway and James Franco, and the opening to the show was a montage of movie clips from that year with the two hosts cut into the scenes for comedic effect. Not only was it pretty much exactly what we are doing now, but it is quite funny and incredibly well done. Check it out:

And for all we know, maybe they used Mocha as well :).

Mocha and Tablets

On Thursday when we worked with Mocha, I had a bit of trouble in my clip with some tracking. I had a clip of a mobile device and there was a lot of activity around it so the program did not track perfectly. I found this on the internet and even though it was designed for CS5 it still seems to be decently effective. I've still got some work to do on the project file I started, but it was definitely a step in the right direction. Video is below:

Mega64: TODD & AARON'S GAME AWARDS 2012!!!!!!!!!

While the title of the video may seem a bit... insane, this video shows a lot of what we did in class on Thursday.

This video was made by Todd and Aaron of Mega64, a series of videos that would combine video games and the real world together.

As you watch the video, you can easily see that the guys are using a Green Screen. It's possible that this video was edited with color keying in After Effect or any other editing software. In some parts of the video, there has been a "Track Camera" motion used as the background would move with the characters (mostly in the end of the video).

This video is about two guys yelling and over-exaggerating about what's the best game, characters and more hilarious things.

I suggest you check this video out, but beware, there is some colorful language!

Tracking

I didn't have a whole lot this week to talk about. However, I did realize from my experience in the LA Program that the suspects cars and cop cars from CSI: NY had tags on them that said demo car and such. I was always wondering how they can cover that up with a real license plate in the actual television show. I realized it's done through tracking just like in the project we did in class with replacing and advertising sign on a taxi in New York.

No Ad: New York

Many are familiar with Morgan Spurlock because of his hit documentary, Super Size Me. He's worked on a number of great projects since that film but one of my favorites happened to be very similar to something we covered in class the other day. When using After Effects to change billboards in New York City's Time Square, I immediately thought of No Ad: New York, Spurlock's project against visual pollution in NYC.

Spurlock, however, takes a different approach to removing ads than we did. Instead of using a program like After Effects, he crowd-sources his project with the help of Aviary, an online photo and graphic editing suite. For this project, a panoramic image of NYC has been divided into many frames that can be individually edited. Anyone who visits the site can select a frame and edit it using Aviary's Photoshop-like software. The goal is to have visitors cover up the ads in all the frames to remove Times Square of its visual pollution. 

It's disappointing to see this project still incomplete, especially since it was started over two years ago, but hopefully it can be completed soon. After learning how to cover up ads in After Effects using tracking, it seems like a very easy goal to accomplish. I feel the decision to crowd-source internet users to complete the project frame by frame was a bit of an ambitious idea.

Chance to practice Green Screen

So I was looking up different green screen works when I found this. It's called Hollywood Camera Work and it's basically a site dedicated to practicing green screen and other visual effects. It allows you to download different pieces of each scenario for free, and while it might look a little cheesy, it provides a good chance to practice "keying, matchmoving, compositing, tracking..." with a green screen.

Again, this site seems like it would be really helpful for the basics of After Effects so check it out.

Practice matchmoving and chroma keying. 

 

Practice Tracking.

If you use these with other tutorials, like those on Video Copilot, I think they would prove really helpful, especially since we don't usually have access to actual videos with green screen.

Motion tracking, deer and dubstep

This video is awesome. The director was obviously passionate about venison and dubstep. It's funny how well the footage and graphics compliment the music. here is the link: http://vimeo.com/20800127

Is there a way I can embed vimeo videos into my post?

DIY movies are fun!

I really like these guys' solution to frozen-time to go!

The Mystery Guitar Man

Hey folks,


I liked this video, although I didn't watch it in 3D yet. "The Mystery Guitar Man" produces weekly shorts that look to me like they make use of AfterEffects tracking functions. A little entertainment and some inspiration as well.