Android emulator camera custom image

Under Tools > AVD Manager, select the "pencil" to get to "Virtual Device Configuration". Show Advanced Settings > Camera will give you the option of using emulated, or a device:

Device - use host computer webcam or built-in camera

If all you need is to get a still image into the camera, starting with Android Studio 3.2 you can put your static images into the virtual scene:

as discussed in this entry from Android developers blog. Note that you'll need to move the camera position into the dining room to see your images (turn around and use Alt-w to move forward).

Finally!

1. Append to file ~/Android/Sdk/emulator/resources/Toren1BD.posters

poster custom
size 2 2
position 0 0 -1.8
rotation 0 0 0
default custom.png

2. Place 'custom.png' in ~/Android/Sdk/emulator/resources/
3. Restart! emulator @Phone -no-snapshot -no-boot-anim (replace 'Phone' with the name of your avd! (see: emulator -list-avds)
4. Profit!

Now you have a texture just in front of camera-default-position.