Automatic Refinement and Filtering

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Automatic Refinement and Filtering should be applied after Manual Clean-up, if there were tracking errors.

Also, this final step is called Post-Processing and includes:

Clean-up Steps
  1. Tracking Refinement
  2. Jitter Removal
  3. Trajectory Filtering

Tracking refinement

After the primary tracking and cleanup are complete, you can optionally run the Refine pass (see Refine Forward and Refine Backward buttons). It slightly improves accuracy of pose matching, and can automatically correct minor tracking errors. However, it takes a bit more time than the primary tracking, so it is not recommended for quick-and-dirty tests.

Important! Refine should be applied:
  • Using the same tracking parameters as the primary tracking (e.g. feet tracking, head tracking) in order not to lose previously tracked data.
  • Before motion controller data.
  • If you plan to manually edit the animation (not related to automatic cleanup with Refit Pose).

In contrast to the primary tracking, Refine does no pose prediction. It is based on the current pose in a frame only. Essentially, running Refine is equal to automatically applying Refit Pose to a range of frames which were previously tracked.

Post-processing: Jitter Removal

  • Jitter Removal filter is a powerful post-processing filter. It should be applied after cleaning up tracking gaps and errors.
  • It is recommended that you always apply Jitter Removal filter before exporting animation.
  • Jitter Removal filter suppresses unwanted noise and at the same time preserves sharp, dynamic motions. By design, this filter should be applied to relatively large segments of animation (no less than 50 frames).
  • Range of frames affected by Jitter Removal is controlled by current Region of Interest (ROI).
  • You can configure Jitter Removal options for specific body parts. Default setting for Jitter Removal “aggressiveness” is 1 (one tick of corresponding slider). Oftentimes, you can get better results by applying a slightly more aggressive Jitter Removal for torso and legs. Alternatively, you may want to use less aggressive Jitter Removal settings for sharp motions like martial arts moves.
  • Jitter Removal filter makes an internal backup of all data produced by tracking and clean up stages. Therefore, you can re-apply Jitter Removal multiple times. Each subsequent run works off original tracking/clean-up results and overrides previous runs.

Post-processing: Trajectory Filtering

  • Trajectory Filter is a traditional digital signal filter. Its purpose is to filter out minor noise that remains after Jitter Removal filter.
  • Trajectory Filter is very fast. It is applied on-the-fly to current Region of Interest (ROI).
  • Default setting for Trajectory Filter is 1. Higher settings result in multiple passes of Trajectory Filter. It is recommended that you leave it at the default setting.
  • Trajectory Filter can be useful for “gluing” together multiple segments of animation processed with different Jitter Removal options: change the Region of Interest (ROI) to cover all of your motion (e.g. multiple segments processed with different jitter removal setting); change Trajectory Filtering setting to 0 (zero); then change it back to 1 (or other suitable value).