Neutral Frames in Faceware Analyzer are frames from the tracked video that are chosen by the user as being "neutral," lacking any facial motion or discernible expression. They can be thought of as the default position of the face. Using the Neutral Frame feature in Analyzer is beneficial in two specific ways:
- When Autotracking in Analyzer, the inclusion of a user-specified neutral frame tells the software where the face is and where the important features are. While Autotrack generally does a good job of recognizing the face on its own, there are occasionally faces that are more difficult for it to recognize and track. Including a neutral frame helps to correct this and increase the fidelity of the tracking results.
- The user can include the neutral frame when parameterizing a finished job in Analyzer. This data gets used in the calculations that convert the tracking to a .fwr performance file used in Retargeter. When Autosolving in Retargeter, a .fwr that includes this data will provide for a more accurate and higher quality initial animation.
What is "Neutral"?
The term "Neutral" in this case refers to a pose where the actor is completely relaxed and shows no tension or expression on their face. You could almost think of it like a Facial Rig in it's default state, when all of the controls are turned off. The actor should be relaxed with their mouth closed, show no emotion on their face, and be looking straight forward. This pose will be matched up with your facial rig's default pose so it's important to get as close to neutral as possible. This may require shooting a short video of the actor in a relaxed state so you can grab a suitable Neutral Frame.
How to Create a Neutral Frame
With your job open in Analyzer, scrub through the timeline to find a frame that you feel is Neutral as denoted by the description above. Below are a few examples of Neutral Frames.
Autotracking with a Neutral Frame
1.) Open the Autotrack dialog as normal.
2.) Using the "Browse" button next to the Neutral Frame field, find and select the Neutral Frame file appropriate to your actor.
3.) Once your appropriate tracker is selected, hit the "Auto Track" button as normal.
Parameterizing with a Neutral Frame
1.) Once your job is tracked, select the option to Parameterize (F12) as normal.
2.) Add the location of your Neutral Frame to the "Current Neutral Frame" field manually or by using the "Browse for Neutral Frame" button.
3.) Once all of your settings are correct, hit "OK" to parameterize as normal.
*Note: Nothing is different on the Retargeter side if using a Neutral Frame. Autosolve the animation as you normally would.