Improve accuracy of hand/face collision

[barbeau]

The current lens works, but the accuracy could likely be enhanced. Sometimes it seems collisions aren't detected when they should be.

A few possible strategies to explore:

1. Adjust the input parameters for Box 1 and Box 2 AABB Script in "Inspector" window
2. Adjust the size of Box 1 and Box 2 in "Scene" window
3. Adjust the size of Box 2 for the head in the "Scene" window
4. Adjust the "Attach To Point" for "Head Binding 0" - currently it's "Head Center", but perhaps another option would work better.
5. Change Box 2 bounding box not to scale with the hand detection. I recall seeing this setting when I was initially adding the feature but can't find it now.

A key difficult seems to be keeping the bounding boxes large enough to detect collisions, but not too large that they hide the hand while it touches the face (it doesn't seem like it detects the hand if it's within the Head bounding box).