[ This article was first published in the December, 2009, issue of
Larry’s Final Cut Pro Newsletter. Updated Feb. 2010. Click here to subscribe. ]
IMPORTANT NOTE: As you’ll discover, this review created a lot of comments, both positive and negative. Imagineer Systems asked me for my demo file so they could review it. In doing so, they discovered that I created a video that was difficult to track. Please be sure to read Ross Shain’s comments on my demo file at the end of this review. I appreciate their interest and feedback.
When I first discovered the motion tracking in Motion 2, I was really excited. It was fairly easy to learn, easy to use, and delivered great results. While I don’t do a lot of effects, it was nice to have this technique in my tool kit.
Time passed. A few months ago, Ross Shain, from Imagineer Systems asked me if I wanted to review the newest version of Mocha. Mocha does motion tracking and the new version is specifically designed to work with Final Cut Pro.
Imagineer Systems has been heavily promoting Mocha through user groups and email blasts, so I’d been hearing about it for a while. I told Ross that I was interested and he sent me a demo copy of the software.
I installed it about three months ago and it has been sitting on my system since then, troubling my conscience. So I set myself the goal of writing a review for this issue of my newsletter. However, that proved to be a bigger challenge than I expected.
NOTE: I am not an effects wizard. If I were, I’d probably write an entirely different review. Instead, I approached this review from the point of view of someone who is knowledgeable about Final Cut Studio and is looking to add new effects software to their system. In other words, a new user of this software.
TWO KINDS OF MOTION TRACKING
There are two ways of doing motion tracking. Some tracking software, such as Motion, uses points to track how an image moves over time. Others, such as Mocha, defines the shape as a plane; called a “planar” tracker.
The benefit to tracking points is that they are easy to explain and to implement. This tracking works reasonably well for objects that move horizontally, vertically, rotate, or change in size. However, the limitations of this technique is that it does not do a good job on objects that change perspective.
The benefit to a planar tracker is that it handles perspective changes very well, at the expense of simplicity and fast learning curves.
Let me illustrate.
Here’s a test clip of me holding a white card and moving it from camera right to camera left. Notice that while the shape of the physical object (the card) remains the same, its shape on camera changes as I change the angle of the card to the camera.
Here’s the problem. The point-based motion tracker in Motion has no ability to change the perspective of the foreground sign. In other words, the motion track is “perfect,” but the results are unacceptable. (Um, I borrowed the line for the sign from an REO Speedwagon album.)
NOTE #1 : This screen shot is mocked up to illustrate my point. The tracker software would change the size of the card as the card changes size, but not perspective; see Note #2 (below).
NOTE #2 : While Motion does allow 4-point corner tracking using points, the tracker totally failed on my sample clip.
I used the top corners of the card for the location of my tracking dots. When the card gets in front of my gray T-shirt, the motion tracker can’t distinguish between the top right corner of the card and my gray T-shirt. In the screen shot above, the red cross is locked on my T-shirt, not the card. So, it decides to follow the T-shirt and the track breaks. This could be solved by putting tracking dots (dark marks) on the card, but I didn’t know this would be a problem until after I started working with the footage.
NOTE #3: The other problem with using the motion tracker in Motion to follow the four corners of an object is that the two bottom corners are obscured by my hands which also causes the tracking to break.
These three important notes illustrate a key point: It is critical to test your ideas before getting into the heat of production to make sure you can actually do what you are hoping to do.
In this case, Motion can’t track this card.
TRACKING USING PLANES
As you may remember from high school geometry, a plane describes a flat surface extending out infinitely in two dimensions. As that plane moves around, any objects attached to that plane will change their perspective.
In other words, Mocha has the ability to solve the problem of perspective changes created by the changing shape of an object as it moves thru space by tracking it as a plane, instead of a couple of dots.
And, Mocha now integrates with Final Cut Pro. So, let’s see if we can use Mocha to solve this tracking problem.
What Mocha does is that it turns the object you want to track into a plane, then generates tracking data to be applied to the foreground clip in Final Cut. You could do the same thing manually using the Distort settings in the Motion tab, only Mocha is much faster and MUCH smoother.
GETTING STARTED WITH MOCHA
I found getting started with Mocha a very frustrating experience. This is because I decided to read the manual and watch one of their generic tutorials Imagineer had posted to the website.
After watching, I was far more confused than when I started.
Then, I discovered Ross Shain’s Mocha demo for Final Cut – also posted to the Imagineer website – which was far superior to anything else they had. (For more thoughts on the power of bad training to scare customers, refer to my editorial later in this issue.)
However, Mocha is not like most other Mac applications. It doesn’t look like any application in Final Cut Studio and it doesn’t act like it. It took me hours to finally figure this out. So, to save you time, let me walk you thru the steps.
Here’s the basic workflow:
OPENING MOCHA AND IMPORTING YOUR CLIP
Mocha only allows one clip to be open at a time in a project. This means that you only need to import the background clip, the one that has the object you want to track — in my case, the clip of me holding the white card.
When you first start Mocha you see the opening screen. This screen looks really impressive, but does absolutely nothing. When you actually try to do something, as I did, you’ll get really frustrated.
This is because this opening screen is not a new project. its just a screen.
To create a new project so you can import a clip, you need to do one of two things:
1. Choose File > New Project (or press Command+N) — or —
2. Open Mocha so you see the opening screen, then drag your clip from the Finder on top of the Mocha icon in the Dock. (Don’t drag the clip directly into Mocha, it won’t work. Nor will dragging a clip out of Final Cut onto the Mocha icon.)
Either way, Mocha displays the New Project Wizard. If you dragged a clip onto the Mocha icon, you’ll see your clip name displayed at the top of the window. This is the first of three setup screens you need to complete.
If you simply created a New Project, click the small orange folder in the top right corner to display a file picker dialog to select the file you want to import.
By default, Mocha stores your project data in the same folder as your source clip. I prefer creating a separate folder for my Mocha data, so I created a folder on my second drive titled: Mocha data. Then, clicked the Absolute Path button to point to that new folder.
To point to this drive, change the Project Output Directory to Absolute, and click the lower orange folder button on the right side, to display a file picker window and select the folder you want project data stored in.
Click the Next button in the lower right to move to the second setup screen.
By default, Mocha uses the entire duration of your clip. In this second screen, you can set the playback range so you are just tracking a portion of the clip.
To adjust this, change the frame settings in the First Frame and Last Frame text boxes.
If your clip is stored locally on a hard disk, uncheck Cache Clip. If your clip is stored on a slow device, like a server, checking Cache Clip will speed performance.
In this case, my clip is on a fast second drive, so I’ll leave Cache Clip unchecked.
This is the third set-up screen.
The only KEY thing to verify is to be sure that the FPS (Frames per Second) frame rate exactly matches your clip. Otherwise, bad things happen.
In my case, all these settings are correct, so I click Finish in the lower right corner.
And you are now ready to start. Whew.
SIDEBAR: CLOSING A FILE AND NOT SAVING CHANGES
Let’s say you imported the wrong file, but didn’t realize it immediately. To close a file and not save changes is particularly obtuse in Mocha. Let me illustrate.
Select File > Close Project. This opens the Save Project window. If you click OK, the file is saved in the project location you specified when you first created the project.
However, if you UNcheck the Save project checkbox in the lower left corner, your project is NOT saved. By default, Mocha always saves your project. Which means you need to pay really close attention if you want to reset your project without saving changes.
In other words, OK either saves or doesn’t save your project. This is the only Mac application I know of with this non-standard way of saving or exiting a file.
Also, as another non-standard behavior, closing a project also quits Mocha.
MOTION TRACKING A CLIP
Now its time to track the clip. Mocha defines areas using either splines or Beziér curves. Mocha recommends using splines, so that’s what we’ll use.
Go to the tool bar at the top and select the Spline tool. Splines are saved to layers in Mocha.
Starting outside the area to be tracked, click once to set a starting point. Then, click to draw a rectangle around the object to be tracked. Be sure to include the entire object.
IMPORTANT: Control-click or right-click AFTER setting the last point to close the shape.
Grab the dot at the end of a control point and drag it to determine the sharpness of the corner.
NOTE: Once you have set a shape, there is no way to delete it. The only way to delete a spline is to select each point and delete it by pressing the Delete key. One at a time. Nor is there a way to delete tracking data once it has been created. The only way to reset a project to is close the existing project without saving changes. This inability to remove splines and reset data is a major frustration. You can remove layers, but not the objects on a layer.
In the lower portion of the screen are three tabs: Clip, Track, and Adjust Track.
According to Mocha, tracks will be better if you reduce the Min % of pixels used to less than 50%. So, I set mine to 40%.
Also, because we want to track changes in Perspective, be sure the Perspective checkbox is checked in the Motion section. It is off by default.
The symbol for the playhead is a small vertical black bar, which is almost impossible to see when it is at the beginning or the end of a sequence. Tasteful is nice, but seeing an essential part of the interface is far nicer.
Reset the playhead to the start of the clip by pressing the far right Go to In button. While this step isn’t really necessary, as Mocha can track in reverse from the end of the clip, it helps me to see things progressing normally.
Once you have defined the area to be tracked, and assuming your playhead is at the head of the clip, press the Track Forward button.
Tracking speed depends upon the speed of your computer and the length and complexity of your clip. However, this would be a perfect time to go get a cup of coffee and visit with your family.
Once the track is complete, you need to fine-tune what the data is that will be exported. This is a process Mocha calls: Adjusting the Track.
ADJUSTING THE TRACK
On simple shapes, Mocha may not need any adjustment. However, on this move, from one side of the screen to the other and back again, watching the position of the surface showed problems with the track.
To see the precise effect of your track on this object, click the Surface button on the right side of the window. This displays a small blue rectangle superimposed near your tracked object. Grab each corner of the rectangle and drag it so that it matches the shape of the surface.
This is an essential step, as this determines the precise data that Final Cut will use to create the finished track.
NOTE: According to Mocha, the surface rectangle can not be keyframed. This means that if there is a problem, you can’t fix it by adjusting the shape of the surface rectangle. You need to add tracking keyframes; which I’ll talk about in a minute.
You can also get a sense of the perspective of the track by clicking the Grid button, just below the Surface button. This shows a planar grid that tracks with your object.
Notice that by the time I moved the card to in front of me, the blue surface rectangle was off on three of four corners. This means that my track has already started to develop errors.
Position the playhead on the frame you want to adjust and click the Adjust Track tab in the lower left corner. This sets a tracking keyframe to allow you to adjust each of the four corners of your surface.
NOTE: Mocha recommends creating as few keyframes as possible, to keep your tracking as smooth as possible.
To make this adjustment process easier, Mocha provides closeup images showing the selected reference point so you can compare the original position of the tracking point with the current setting of the reference point.
After you make all necessary adjustments, so that the surface rectangle tracks properly with the movement of the object, you are ready to export your data. In this example, I spent about 45 minutes creating keyframes and adjusting the track.
In creating my track, I was surprised at how many adjustments I needed to make. The corners kept drifting. In this nine second video, I needed to add six keyframe adjustments to the track.
NOTE: In doing this track, I realized I made a big mistake in production. Notice in the video tutorial Imagineer created, the four corners of the object are clearly visible at all times. In my video, my hands covered the two lower corners, which made finding consistent reference points impossible.
This meant that two of the key references Mocha needed to create a track were obscured by my fingers. I clearly did not think about this when I shot the video. But it made my motion tracking far harder, and less accurate. For this reason, it is essential that you think through any special effects you plan to use before you shoot your video.
EXPORTING TRACKING DATA
All Mocha does is create tracking data. All compositing and finishing are done in Final Cut Pro. Which means that we need to get the data out of Mocha and into Final Cut.
Click the Track tab at the bottom of the main window. If Export Tracking Data is grayed out,
… click the magenta bounding box surrounding your object in the Canvas window to select it.
By default, Mocha labels layers as Layer 1, Layer 2, and so on. You can rename a layer by clicking it in the top left corner, under Layer Controls. In this case, I gave it a more helpful name.
Click Export Tracking Data to export your data. Getting data back into FCP requires creating an XML file.
There are two types of files that can be created: Motion and Distort. If your object is changing position, using Motion. If your object is changing perspective, use Distort.
In this case, I selected Final Cut Distort.
Click the Save button, give your soon-to-be-created file and name and location and click Save.
At this point, you are done with Mocha. Save your project if you want to refer back to this later: File > Save Project. You can now safely quit Mocha.
FINISHING THE PROJECT
I created a Final Cut Pro project containing the background clip and a sign to insert into the background based on the motion track data we just created.
To import the motion track data, select File > Import > XML and navigate to the motion data file.
In the Import XML dialog, be sure to select the project file you want the clip to import into. Keep all three options checked, and click OK.
A new clip appears in the Browser — the motion tracked clip you just created in Mocha. It is highlighed in this screen shot.
To copy the tracking data for pasting onto a new clip, Control-click the XML clip and select Copy.
Select the new foreground clip in the Timeline and choose Edit > Paste Attributes.
In the Paste Attributes dialog, turn OFF Scale Attribute times and turn ON Distort. Click OK.
NOTE: If you exported using Motion data, you would uncheck Distort and check Basic Motion.)
Play your clip and see how the new sign is tracked onto the background.
NOTE: For better results, try using Modify > Composite Mode (in this example, I’m using Multiply).
After watching the demos and reading the manual, I’m convinced that Mocha creates motion tracks that can’t be created any other way. And, if you have a background in effects software, you will probably find Mocha easy to use.
However, I was extremely disappointed in the quality of Imagineer System’s on-line tutorials – they showed without teaching. (Ross Shain’s tutorial was the notable exception.) The tutorials were geared to people who already knew what they were doing, not to people who were trying to learn. I found them very frustrating.
The Mocha manual did not provide answers to common problems experienced by new users, not did it provide tips on how to shoot materials that need to be motion tracked. The inability to delete splines or reset clips, non-standard file saves, and adjusting mis-behaving tracking points I found disconcerting.
I was also surprised by the number of errors that appeared during the creation of the track.
Integration with Final Cut is about as good as Final Cut will allow, so, while cumbersome, that isn’t Imagineer’s fault.
If a significant amount of motion tracking is in your future, Mocha should be considered. However, if you are new to the field, allow plenty of extra time for learning and experimentation. Also, expect to be really, really confused for a period of time as you are learning the software.
Finally, remember that the key to creating great looking effects is spending time thinking about how to shoot them in production, not trying to figure out how to fix it in post.
UPDATE – Jan. 2, 2010
Nicolas Nilsen writes:
I agree totally. Each tutorial should have – at the end – not only a chapter dedicated to troubleshooting but also, in some chapters – some sort of warning going like this : “here you might be tempted to proceed like this, because it seems obvious – well don’t, because (showing the mistake) this is what you would get…”. I mean that sometimes, showing the mistakes is as useful as showing the right way. Anyway, you’re right Larry : the idea of a good tutorial is for us to be able to cook and eat the damn rabbit ; not just see how easy it is for you to kill it ! With all my best wishes for 2010.
Norman Hollyn sent this in:
Great points in regards to tutorials. Marketing departments at the major software manufacturers should get their hands off of tutorials. There’s a place for what they do — on the sales pages. But, too often (in their urge to “brand” themselves and their products) the marketing departments are given license to create or, at least, vet the tutorials. This is a recipe for disaster.
In regards to the form for a tutorial, a pretty good rule for any sort of teaching is to do the following three things:
1 – tell people what they are going to learn,
2- teach people,
3 – tell them what they’ve just learned.
This helps the “student” to situate themselves within the teaching. And most people, especially the creative types who you are working with, work better when they can see the overall picture of their learning.
Mark Spencer adds:
Great article. I’ve been working with Mocha for FCP as well and have to agree with many of your comments. There’s an interesting workflow that extends on what you did by then sending a clip from FCP to Motion with the tracking data for further refinement which I’m planning to explore in a future tutorial.
Anyway, I think Mocha is a very good product with an obtuse UI and poor documentation but a lot of promise, and they are lucky to have Ross to help make it easier to understand.
Great points also about the distinction between a demo and a tutorial.
Kit Laughlin, from Kambah, Australia, adds:
Lastly, as a workshop presenter myself, I loved your analysis of Motion. This is THE problem in learning new software: the tutorial authors assume that the newbie understands the context in which the new software is situated, or that the newbie understands how the software thinks. Explaining how a function in some Tab works is not a substitute for this scene-setting. A huge two thumbs up to you for pointing this out.
UPDATE – Jan. 4, 2009
Ross Shain, from Imagineer Systems, writes:
Hi, Larry. Thanks for your honest critique. I really appreciate your time and willingness to put mocha for Final Cut and the materials through the paces. It is clear to us that the FCP market requires a different type of training and docs than we currently provide. Imagineer’s history and experience has been in high end visual effects and some of our challenges to reach a wider market (especially in editorial) are illustrated in your blog post.
I would like share that we do get emails every day from users who rave about mocha, its ease of use and how it has changed people’s workdays. The fact that Adobe bundles our products and recent customer survey results show me that we are doing something right for many users and markets.
But believe me, in no way does this invalidate your opinion and I completely agree with many of your points. I will do my best to have some of these training and documentation issues addressed. We know that Mocha is a very valuable tool.
Larry replies: Thanks, Ross, for sending this. I am always very reluctant to say bad things about any product, because I know how much work is involved in creating anything. I think that Mocha has a great deal of potential, once some clearly fixable things get fixed.
Stace Carter, adds:
Larry, I’d agree with you that Mocha isn’t incredibly intuitive – I also found that as a new Mocha for FCP user I realized early on that without a fairly comprehensive understanding of FCP many users would be completely lost. That being said, what this app helps you accomplish is not simple stuff – generally relegated to the higher-end of effects and finishing. Planar tracking, for those who’ve had to roto frame by frame, is just like magic 😉 The fact that I can track HD footage on my laptop and finish the comp in FCP, in just a few steps, is even more magical.
SO… while I can’t completely disagree with you about the out-of-the-box simplicity of the instructions, I feel you’re overlooking the amazing support that’s available from this great company. I posted a few early questions to the Imagineer support forum and received quick, thoughtful and helpful replies from Martin Brennand – the kind of assistance one would never expect from a software company these days.
Like yourself, I also work as a trainer and understand that teaching (or more importantly, helping folks learn) involves a unique approach and skill set, not just knowledge of the topic. With that in mind, I can’t justify holding the Imagineers feet to the fire for not having better tutorials – they are obviously a small, nimble and talented company and focus on what they do best. At worst, I think their emphasis on product design – and customer service – simply leaves an opportunity for folks like you and me to teach more seminars and classes.
PS – In re-reading this post I sound like I work for these guys – I have no dog in this fight, I was just really impressed with the level of service I received from Martin and feel you’ve overlooked an important aspect of the company and product, the great customer service.
Larry replies: Thanks, everyone, for your thoughts!
UPDATE: Jan. 5, 2010
Ross Shain, of Imagineer Systems, writes:
Larry, thank you for posting your demo file for me. Here are a few things to note.
I watched the file and could immediately see some of the issues that you had with your track. There is no detail in the white paper that you are holding, the bottom 2 corners are obscurred by fingers and there is a shadow that comes and goes. In a situation like this, often the DP or effects supervisor would add small track marks on the object the actor is holding to aid the tracker and save time in post.
The good news is even while most experienced compositors would agree with me that your shot is not a simple track, with mocha I was able to get a very good result within 15 minutes including the time it took to add some adjust track keyframes.
1. The shape that you created is too large – without any detail on the paper and with the shadow, it is important to create a “pattern” in mocha that is trackable. All the pixels in a defined shape represent a pixel pattern that mocha uses to find on the next frame. See the attached screen shot to see the shape I used as a search area. It ends up being very similar to the shape I created and demonstrate in the mocha for Final Cut QuickStart tutorial.
2. I left the “minimum % of pixels to use” in tracking tab at 90%. This parameter can aid a track’s accuracy depending on how much detail is in the actual shot. I left it at the default for this shot.
3. While tracking as the hands move a little, I stopped the tracker and adjusted the actual shape a few times, and kept tracking.
4. Lastly, I did need to add some adjust keyframes…about 15 which is really not bad for this duration clip with the problems described.
I will see if there is time this week to do a tutorial on this shot. Because of the issues described, it doesn’t make for the most glamlourous tutorial and in general while I agree with many of the user comments a tutorial is not a demo, there is an element of interest or excitement to consider when choosing the right footage to focus on. Either way, I do hope that this is useful for you….
Again, I am sorry that you got so frustrated in your training process and do wish you had contacted me during this time. I think that most of our customers, even those that start off frustrated, end up being huge fans once they get over the learning curve.
Lastly, one of the largest features in mocha for Final Cut and mocha shape FxPlug is the ability to track and cut mattes for color correction, blurs, etc. I am confident that this is a very useful feature as FCP is so limited in roto and matte creation. If you can overlook all the issues you have had so far, I am sure that you and your readers would find this very useful.
Mocha Shape is detailed here:
Larry replies: Ross, thanks for showing ways to improve the tracking results with Mocha.
What might be more useful than simply creating a tutorial is to explain what makes good video for tracking. Feel free to use my video as an example of what not to do and illustrate what should have been done instead. This kind of comparison would be MUCH more useful than just another tutorial.
As I mentioned in my review, proper planning before shooting effects is critical. However, if you don’t know what to plan for, you end up with very difficult material to work with.
In the December issue I did an extensive review of Imagineer System’s mocha. In brief, I thought the product did things that could not be done by either Final Cut or Motion, but it had a very hard to learn and non-intuitive interface, compounded by on-line training and documentation that made the product very difficult for users new to motion effects to learn.
This review generated a lot of comment from readers, and from the folks at Imagineer Systems. Based on that review, and other user comments, they have redone a lot of their on-line training targeted at the Final Cut Pro user and are working on a new version of the program to be announced soon. In addition, since they are based in the UK, they invited me to meet with their lead trainer on my recent trip to London to learn how to use the product better.
During our visit, I had time to interview Martin Brennand about mocha. Martin is the chief trainer for mocha. After talking with Martin, and reading comments from Ross Shain at Imagineer, I learned something that I wanted to share with you.
Based on Ross Shain’s feedback from the article I made a mistake when my hands covered the corners of the card I wanted to track. Since the card was white, and the corners were sometimes visible and sometimes not, mocha didn’t have enough consistent information to know what to track.
So, I went back into the studio and reshot the video with a new card and holding it differently. I wanted to demo mocha as part of my seminars in the UK, so I created what I thought was better video.
However, I still screwed up. When I met Martin, he told me that motion trackers like to track something with texture, or contrast, in the object being tracked. Because I used a plain what card, it was very hard for mocha to find specific elements within the object it could grab and track.
Next time, Martin suggests holding an actual sign with text, or adding marks to the surface that could be used as tracking dots; moving an object with no detail is very difficult to track.
You can find more about how to shoot for motion tracking in this video tutorial on the Imagineer website.
I want to thank the folks at Imagineer Systems for their comments to my review, and for marking Martin available during my visit. I’m also looking forward to seeing what’s new in the next version.
However, my experience also illustrates something the rest of us need to keep in mind. If you are thinking of doing fancy effects in post-production — TEST YOUR IDEAS before going into production. I’ve learned I need to be careful selecting the object I use to generate the track, where I hold my hands, and the difference between the object (in this case the color of a card) and the background (the color of my shirt).
This has been an interesting experience and I suspect there is still plenty more to learn.
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