When you switch to body capture mode you may be asked to pan your device around the scene. This is required so that ARKit can identify the environment to correctly determine the position of your actor.
Once ARKit has enough information you will then be asked to "Walk in front of the camera". If your actor is in front of the camera they can now be detected and a robot overlay will appear on the screen.
When your actor has been detected you can now press the record button at the bottom of the screen.
It is best if your actor wears clothing that contrasts with the background. For example, choose light colored clothing if the background is dark.
Your actor should also not be wearing any loose fitting clothes such as baggy jackets, or skirts/dresses since they will obscure the actors legs.
When performing the actor should make slow movements and try not to cross over their arms or legs too much.
The capture quality will be affected by many different parameters including how recent your apple device is, the lighting quality of the scene, the speed of the actor movements and other factors.
By tapping the 30/60 icon on the top right you can change the frame rate at which the capture will be recorded. When you tap you will see a message appear telling you what FPS it is being set to.
When it displays 30 it will record 30 frames per second. When it displays 60 it will record 60 frames per second.
Press the flip camera button to change to Face Capture mode.
Press the X on the top left to close the camera and go back to the capture list.
Press the white record button to start capturing.