how to chop off pieces of a face and some more

Hi Image Fatale,

This will be hard to do since it would be very difficult to know what's behind the person's head. 

One strategy you can try is to have the user save a picture of the background and then overlay their face afterward using segmentation. 

To save a picture of the background:

1. Create a new camera (Objects panel > Add New > Camera) and set its source to Device Camera Texture.
2. Then you can display the result of this camera using a billboard (Objects panel > Add New > Billboard).
3. Select the new billboard, and in it's Inspector panel, press the Field texture.
4. In the pop up, press (Add New > From Camera > select your newly created camera).

Now, when you disable the camera you created, you should see that in your Preview panel, the camera has paused on the last frame. You can disable the camera by using something like the Behavior Script.

Next we can add the user's body on top of the frozen frame:

1. Create another billboard as above, and in the new billboard's Inspector panel, press the Material field.
2. Then in the pop up, choose Add New > Unlit.
3. Select the new unlit material in the Resources panel.
4. In the Inspector panel, set it's blend mode to normal (since we want this material to have transparency).
5. Then select the texture field, and in the popup, choose Camera Output Texture.
6. Finally to segment this billboard, tick the Opacity texture field, then select the Texture field underneath it. In the popup window choose Add New > Segmentation > Portrait background. 

Your final Objects panel should look something like this:

Here's an example project using the steps I described above. 

Let me know if you need any clarification.

Cheers,

Jon