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Dual-Camera Motion Capture

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Requires v0.17.0 or later.

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This feature is experimental. Accuracy may degrade in certain postures, and we are working on improvements.

Overview​

Dual-camera motion capture is a feature that performs motion capture using two iPhones. Compared to the standard single-camera setup, it enables more accurate pose estimation.

With a single camera, only frontal information is available, making it difficult to accurately capture depth movement and body rotation. By filming from different angles with two cameras, three-dimensional movement can be reproduced more accurately.

Required Equipment​

  • 2 iPhones (with the capture app installed)
  • 2 smartphone holders (for stable shooting)
  • Same WiFi network (PC and both iPhones must be connected to the same network)

Camera Placement​

Place the two cameras to capture the subject from different angles.

  • Angle between cameras: Approximately 20° to 60° is recommended. This varies considerably depending on the situation. A shallow angle difference reduces depth accuracy. A wider angle makes posture more likely to break down.
  • Distance to subject: Place each within 20cm to 1m of the subject
  • Camera height: Set both cameras at a height that captures the subject's upper body

Placement Example​

        [Subject]
        /      \
       /        \
   Camera 1   Camera 2
  (Front-left)  (Front-right)

The basic setup is slightly left and slightly right of center. Avoid extreme placements that sandwich the subject.

Placement Tips​

  • Place both cameras where they can capture the subject's face and upper body
  • You can check the camera's view range from the eye icon in the iPhone app (restore after checking)

How to Use​

  1. Launch Studio App on your PC.
  2. Set up iPhone connection in Remote App. Press the "Connect iPhone" button on the home page, and scan the QR code with one device on Channel 1 and the other on Channel 2.
  3. Run camera calibration on the avatar page. Since the poses of the two cameras are estimated from the face position, make sure your face is pointing between the two cameras.
  4. Move your hands and verify that depth is being detected.

Current Limitations​

  • Body shaking occurs more frequently compared to a single camera setup. This can be mitigated by increasing the smoothing value in pose control characteristics.
  • Posture tends to break down in certain poses (such as turning significantly sideways or when the face is hidden from the camera).
  • Currently only iPhones are supported (support for cameras other than iPhone is planned for the future).