REALVIZ® MatchMover 2® and MatchMover 2 Professional®
By Jeff Mottle (email@example.com)
In this, part two, of our three part look into the new REALVIZ AEC solutions, we will review MatchMover 2® and MatchMover 2 Pro®. Currently MatchMover 2® is available both as a stand alone product or as a part of AEC Studio. MatchMover 2® Pro is also available as a standalone product or packaged into SFX Studio. Both perform the same function, but the latter is the most recent and more powerful of the two releases.
So, what is MatchMover®? MatchMover® is a MatchMoving application that allows you to capture the 3D camera path and camera parameters from 2D live video, or film frame sequences. Using the captured data you can export camera information to your animation or composition software to facilitate the matching of animated 3D CG footage with your 2D live video. With MatchMover® you can now drive down a street while filming the proposed building site, and capture the exact camera information and movements so that you can composite your rendered building in place. MatchMover® will also work on aerial footage, or any other application where you need to composite CG architecture with existing video footage.
Long gone are the days of having to spend hours if not days out in the field setting up targets, measuring all of them from a known origin, and making meticulous notes for yourself. The results of old camera tracking methods were both cumbersome and extremely time consuming and often yielded poor to mediocre results. Not to mention that this type of manual tracking only worked if you could readily access the environment, or you had the original blueprints of the building or street you were trying to match.
How does it work?
MatchMover® works by tracking selected pixels through an image sequence by comparing a set area around the pixel in each sequential frame. As it moves from frame to frame, MatchMover® analyzes how and where the tracked pixel moves. Tracking numerous pixels throughout the sequence enables MatchMover® to calculate how the camera moves throughout the scene and the camera data like focal length and zooms. From the calculated data you can export a camera path to 3DSMAX, or any of the other supported applications and render out a matching sequence. The rendered sequence will mimic any camera shake, pans, zooms etc.
Depending upon which version of MatchMover® you get, the technique used to track points will differ slightly. I'll start first with MatchMover 2®, the solution that is packaged with AEC Studio.
MatchMover Professional Interface
With MatchMover 2® there are 5 steps to calculate a tracking solution:
1. 2D Tracking
2. Camera Tracking
In the first step, you import the video sequence that wish to track. MatchMover 2® supports AVI, Cineon, JPEG, Maya, PNG, PNM, SoftImage, SGI, TGA, and TIFF file formats as valid import image types.
Step two involves choosing the points that you wish to track through your sequence. To ensure that a good camera match is achieved, points need to be scattered throughout the frame and should be placed on both foreground and background elements. It is also important to keep roughly the same number of keypoints from frame to frame. As you can imagine if is very likely that the same points will not be able to be tracked through an entire sequence, as they usually move out of frame. When this happens you simply choose another point to track in its place. For the next step, MatchMover® must have two reference keyframes which have 7 tracking points in common or 4 with known coordinates, so it is important to keep that in mind when you are placing your points. During the tracking process you have access to numerous preferences, settings and key types that will allow you to tweak your tracks to ensure that they are as accurate as possible.
Once you have established all of your 2D track points you move onto the next step - Camera tracking. In this step MatchMover® automatically calculates a points' position in 3D space and determines camera movement. It is in this step that you also establish a coordinate system by choosing a few of your tracked point to determine an axis system and a scene scale. You can also input any known camera information such as lens and film back information, as well as any know coordinates for tracked points. While it is not necessary to provide all of this information, any additional help you can give MatchMover®, will ultimately speed up processing and ensure more accurate camera matching results.
Graph editing mode
In the last step you export your camera data to your animation or compositing package. MatchMover 2® can export to: REALVIZ® ASCII Point Tracks, REALVIZ® ASCII Camera, XSI, Maya, SOFTIMAGE 3DS, Lightwave files, 3D Studio Max, and Cinema 4D.
MatchMover 2 Professional®
MatchMover Professional® still features all of the capabilities of the original version of MatchMover®, but now allows you to completely automate the process of 2D trackpoint selection and calculation. Instead of manually choosing the points you wish to track, MatchMover Professional® establishes several hundred points to track in the first frame and tracks all of them through the entire sequence. All you have to do is press "Automatic Tracking". Once the tracking has been run MatchMover® automatically chooses the best points and uses them in the camera tracking stage. You can have a much or as little input as to how each point is tracked and even modify tracks after they have been automatically tracked.
You can also run an automatic cleanup stage that removes all tracks that do not fall within a set residual value.
The power of this feature should definitely not be overlooked. The ability to autotrack can save you an enormous amount of time. Also, new to the professional version has the ability to export to Discreet Combustion.
Having only ever done manual tracking with scene targets, I can honestly say that MatchMover® is a godsend for anyone who want to do serious MatchMoving/Camera Tracking. The process is exponentially faster than traditional methods and is significantly more accurate.
It did now take long to figure out how to use the applications, however the documentation in MatchMover Professional® is significantly more detailed and easier to follow than the original MatchMover® version. I did find that both lacked in-depth explanations as to why certain settings were set and the tutorials in places were simple "press this button, then change this setting to x" type. Although not specific to just REALVIZ® products, I find these type of tutorials great for working on the canned demos, but do not help much one you start working on your own sequences. On a positive note, REALVIZ® does offer training for all of it products.
For the most part MatchMover® is a fairly straightforward application to learn. The only part that I had fair bit of difficulty with was setting up a coordinate system. Although you would think that establishing a few axes would be a simple task, I found it even more difficult than selecting and manually tracking my points. It took about 10 tries and re-reading the documentation a few times before I finally got it to work. Maybe it was me, but it seems that this task could have be a bit more user friendly.
My only other complaint was the few Internal errors I received, which fast exited me from the application. It was not too much of a deal as there is a recovery file that was automatically created and I had saved several times anyway.
I should also mention that I had our video guy at work record several short sequences with our BetaCam with very shaky movements and bouncing, as well as a fast pans and zooms and all tracked very well with MatchMover Professional's® automatic tracking. I was quite surprised at just how will it did perform.
Overall I think that both versions of REALVIZ® MatchMover® are extremely powerful and versatile solutions that should be in the toolkit of anyone wishing to do serious Matchmoving.
Give the demo a try and I am pretty confident that you won't be disappointed.
At the time of printing MatchMover® was priced as follows:
AEC Studio - $1,999
Stitcher 3.1, Image Modeler 3.0, MatchMover 2®
SFX Studio - $9,999
Stitcher 3.2, Image Modeler 3.0, MatchMover Professional®, ReTimer
MatchMover 2® - $1,499
MatchMover Professional® - $4,999
REALVIZ® website: http://www.realviz.com
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