In my second 3DE tutorial, I have to apply the tracking method into a human face.
It is also essential to place the tracker point in most recognisable area.
How to identify good reference points in sight to locate a tracker point :
1. High in color contrast.
2. Clearly defined edges.
3. Limit the track region within a same depth.
4. The search region should have sufficient distinction from the track region.
Take my tracking point as an example in below (Figure 2.1):
Especially for trackpoint “02” and “14” (in Figure 2.2), they are high-contrast and obvious stickers of the pole. I also resize the tracker region within the pole area as a long vertical rectangle.
And when all these principles apply to a human face, basically they are the same. With some friendly reminders for myself :
1. The centre trackpoint in the middle of forehead is quite an essential point to determine the rotation of the head.
2. The points for left and right sides on face should be even.
3. Be aware the points which are close to the edge of the face.
For example (Figure 2.3), on the right hand side of the main character, trackpoint “17” is a point that lost its way for a few frames.
Looking at the Pirates of the Caribbean movies as an example (Figure 2.4), the trackpoints on Bill Nighy’s face showing the same technique for animate the facial expression of the character in movie.
Result
The rotation movement is not sensitive enough, as there are no sufficient trackpoints on the character right hand side. But so far, I am quite satisfied with the result.