With bilinear tracking, or four-point tracking, you use four trackers in the Stabilizer to generate tracking data.
- For anchoring the four corners of a bilinear surface to the background clip.
- For anchoring the four UV points of the surface to features of the clip.
The bilinear surface then tracked to the horizontal and vertical translation of the reference points.
See
Stabilizer Menu Settings for an overview of the settings and options in the Stabilizer.
To track a bilinear surface:
- Load front and back clips in Action.
- Double-click the image node in the schematic to display the Surface menu.
- Select Bilinear from the Surface Type box.
- Do one of the following:
- To track the Vertices relative to the background, click the Vertices tab to display the Stabilizer button and tracking options.
- To track the UV points of the surface to features of the clip, click the UV Points tab to display the Stabilizer button and tracking options.
- Select a tracking mode. Options are:
- Each Point: Track the surface using a tracker for each selected vertex or UV point.
- Pos/Rot: Track the surface using two proxy trackers that extrapolate the position of the selected vertices or UV points, based on changes in the position and rotation.
- Pos/Scale: Track the surface using two proxy trackers that extrapolate the movement of the selected vertices or UV points, based on changes in the position and scaling.
- Pos/Rot/Scale: Track the surface using two proxy trackers that extrapolate the movement of the selected vertices or UV points, based on changes in the position, scaling and rotation.
- Click Stabilizer.
The Stabilizer menu is displayed.
Note: The Position, Rotation and Scale settings of the vertices or UV points in Z are reset when entering the Stabilizer.
- Do one of the following:
- Position the trackers on the background clip (Vertice tracking).
- Position the trackers on the surface texture (UV points tracking).
- Gang the trackers.
- Enable Auto Update Reference.
- Click Analyze to generate the tracking data.
- After the analysis is complete, click Return.
The Surface menu in Action reappears. The tracking data is automatically applied to the four corners of the bilinear surface or texture.
- Enable Edit Track in the Vertices menu to edit tracking data directly from the image window without having to switch to the Animation channel. The vertices are displayed in blue when Edit Track is enabled.