You can use planar tracking in your Action compositing workflow on many different types of footage to produce different results. The tracking menu exposes many settings to help you prepare and refine the planar track. Read the following sections for some tips and best practices to get the best possible results out of the planar tracker.
Pre-Tracking Settings
See the full list of settings here or in the tooltips. Here are a few things to keep in mind before you track:
- Look out for rotation, scale, skew, and perspective in your media to be tracked; and enable the appropriate buttons to help the tracking analysis. Of these four buttons, pay particular attention to Perspective; enable it only if the content is planar, and there is perspective information. Enabling Perspective without these may result in instability in the tracking analysis.
- Sampling field (Region Warping algorithm): As a general rule, a larger sampling reference increases the quality of the results, but takes longer. There may be instances, though, when a lower sampling value works better, such as when there is a lot of grain or noise in the media, or if there is fast camera motion. In these instances, down-sampling may actually eliminate these potential sources of confusion for the algorithm.
- Lighting button (Region Warping algorithm): Enable to help with colour variations or high specularity. Enabling Lighting can also help with diffuse reflection in an object, such as clouds in a window.
- Occlusions button (Region Warping algorithm): Make sure that the sequence has occlusions that you don't want to be tracked. Enabling on a sequence where no occlusions appear, may lead to tracking errors.
- Analyze RGB Channels button (Region Warping algorithm): Should only be enabled when colour information can make a difference in a track. When enabled, it could generate a better result than when only Luminance is used, but at the cost of performance.
- In some cases, bad tracking data can be alleviated by selecting Lock in the FOV Adjustments box in the Perspective Grid menu, before tracking.
Analysis Settings
To help you view the tracking analysis as it occurs, switch to Object Solo (F8) view, and make sure that the Shape Reference and Shape Current buttons are enabled in the Display tab.
If you need to fine-tune the tracking analysis, many of the analysis settings are similar to those in the Stabilizer; Step, Snap, and Auto Update Reference should be familiar to you, as well as using the backspace key to delete bad keyframes (it is preferable to delete any bad keyframes before re-tracking). See the full list of settings here or in the tooltips.
- Use Ctrl for added functionality with the Go To Reference button to go to the last analyzed frame, and with the Set button to add a keyframe on the track without doing an analysis.
- Updating the reference can help the track, since it constantly compares the current frame content to the reference, to extract the tracking data. You have two options to update the reference:
- Update it manually when the track is failing, using Snap.
- Enable Auto Update Reference. Using Auto Update Reference generally allows you to perform an easier track, at the cost of stability, since it compares the current frame to the previous (or next) frame, and therefore is likely to introduce offset over time, or instability in the track. Large occlusions or motion blur may also impede the Auto Update Reference.