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In the 3D viewer, the point cloud locators can be sized by this control.
Track Colors, Locator Colors, and Export Colors each have options for setting their color to one of the following:
— User Assigned
— Solve Error
— Take From Image
— White
Track Colors | Onscreen tracks in the 2D view. |
Locator Colors | Point Cloud locators in the 3D view. |
Export Colors | Colors of the locators that get exported within the Point Cloud node. |
Dims the brightness of the image in viewers to better see the overlaid tracks. This affects both the 2D and 3D viewers.
Toggles which overlays will be displayed in the 2D and 3D viewers. The options are Tracker Markers, Trails, Tooltips in the 2D Viewer, Tooltips in the 3D viewer, Reprojected Locators, and Tracker Patterns.
Sets the color of the overlays.
— Selection Color: Controls the color of selected tracks/locators.
— Preview New Tracks Color: Controls the color of the points displayed in the viewer when the Preview AutoTrack Locations option is enabled.
— Solve Error Gradient: By default, tracks and locators are colored by a green-yellow-red gradient to indicate their solve error. This gradient is completely user adjustable.
Outputs various parameters and information to the Console.
Understanding Camera Tracking
On large productions, camera tracking or 3D match moving is often handed over to experts who have experience with the process of tracking and solving difficult shots. There is rarely a shot where you can press a couple of buttons and have it work perfectly. It does take an understanding of the whole process and what is essential to get a good solved track.
The Camera Tracker must solve for hundreds of thousands of unknown variables, which is a complex task. For the process to work, it is essential to get good tracking data that exists in the shot for a long time. False or bad tracks will skew the result. This section explains how to clean up false tracks and other techniques to get a good solve.
Getting a good solve is a repeated process.
Track > Solve > Refine Filters > Solve > Cleanup tracks > Solve > Cleanup from point cloud > Solve > Repeat.
Initially, there are numerous tracks, and not all are good, so a process of filtering and cleaning up unwanted tracks to get to the best set is required. At the end of each cleanup stage, pressing Solve ideally gives you a progressively lower solve error. This needs to be below 1.0 for it to be good for use with full HD content, and even lower for higher resolutions. Refining the tracks often but not always results in a better solve.
False tracks are caused by a number of conditions, such as moving objects in a shot, or reflections and highlights from a car. There are other types of false tracks like parallax errors where two objects are at different depths, and the intersection gets tracked. These moiré effects can cause the track to creep. Recognizing these False tracks and eliminating them is the most important step in the solve process.
Getting a good set of long tracks is essential; the longer the tracks are, the better the solve. The Bi- Directional tracking option in the Tracker tab is used to extend the beginning of tracks in time. The longer in time a track exists and the more tracks that overlap in time of a shot, the more consistent and accurate the solve.
Two seed frames are used in the solve process. The algorithm chooses two frames that are as far apart in time yet share the same tracks. That is why longer tracks make a more significant difference in the selection of seed frames.
The two Seed frames are used as the reference frames, which should be from different angles of the same scene. The solve process will use these as a master starting point to fit the rest of the tracks in the sequence.
There is an option in the Solve tab to Auto Detect Seed Frames, which is the default setting and most often a good idea. However, auto detecting seed frames can make for a longer solve. When refining the Trackers and re-solving, disable the checkbox and use the Seed 1 and Seed 2 sliders to enter the previous solve’s seed frames. These seed frames can be found in the Solve Summary at the top of the Inspector after the initial solve.
After the first solve, all the Trackers will have extra data generated. These are solve errors and tracking errors.
Use the refine filters to reduce unwanted tracks, like setting minimum tracker length to eight frames. As the value for each filter is adjusted, the Solve dialog will indicate how many tracks are affected by the filter. Then Solve again.