Execute calibration

Get intrinsic parameters

• Display this image on your PC's screen as large as possible.
• In MocapForAll, click Start button under Camera > Calibration > Intrinsic.
• Take images with the camera from various angles for about 10 seconds. If the camera is already fixed, move the image instead of the camera.

When calibration is completed, intrinsic parameters will be displayed on the app's screen and Intrinsic ☑Calibrated will be shown.

Save the camera calibration result from Save.

Get extrinsic parameters

The procedure differs depending on the 4 methods to get extrinsic parameters explained before.

ChArUco board methodArUco cluster methodDiamond cluster methodHuman motion method

• Place the image printed in Prepare markers section on the floor. This will be the origin of the captured motion.
• Place the cameras where they can see the placed image.
• In MocapForAll, select ChArUco board (default) in Settings > Calibration > Extrinsic calibration method.
• Click Start button under Camera > Calibration > Extrinsic.

When calibration is completed, extrinsic parameters and the camera position will be displayed, and it will shows Extrinsic ☑Calibrated.

If it does not read the AR marker properly, try If the marker cannot be read properly.

• Place the images printed in Prepare markers section on the floor. arucoMarker0.png will be the origin of the captured motion.
• Place the cameras where they can see the placed images.
• In MocapForAll, select ArUco cluster in Settings > Calibration > Extrinsic calibration method.
• Click Scan markers button under Camera > Calibration > Extrinsic. This will scan the relative positions of the markers. After a while, the markers will appear in the 3D viewport.
• After all markers appeared, click Stop scanning and then Start under Camera > Calibration > Extrinsic.

When calibration is completed, extrinsic parameters and the camera position will be displayed, and it will shows Extrinsic ☑Calibrated.

If it does not read the AR marker properly, try If the marker cannot be read properly.

• Place the images printed in Prepare markers section at a distance that fits in a frame of the camera. It does not have to be in the same plane. diamondMarker0.png will be the origin of the captured motion, so place this on the floor.
• In MocapForAll, select Diamond cluster in Settings > Calibration > Extrinsic calibration method.
• Click Scan markers button under Camera > Calibration > Extrinsic in one of the cameras. Take pictures of diamondMarker0.png and one of the markers at the same time. After a while, the position of another marker will be fixed with diamondMarker0.png as the origin, and the marker will be displayed on the 3D viewport.
• Repeat the above step for markers whose positions have been fixed and markers whose positions have not been fixed, and click Stop scanning when the positions of all markers have been fixed.
• Place the cameras where they can see at least one of the markers whose position is fixed.
• Click Start under Camera > Calibration > Extrinsic.

When calibration is completed, extrinsic parameters and the camera position will be displayed, and it will shows Extrinsic ☑Calibrated.

If it does not read the AR marker properly, try If the marker cannot be read properly.

• Place the cameras so that at least two of them can see your whole body at the same time.
• In MocapForAll, select Human motion in Settings > Calibration > Extrinsic calibration method.
• Select GPU_DirectML in Settings > General > Run DNN on if your hardware support it. (If you have already installed the GPU_TensorRT mode in the Appendix, you can also use it.）
• Select Speed in Settings > General > Capture body if your PC's performance is enough for it. (If you have already installed the Precision mode in the Appendix, you can also use it.）
• Click Start calibration button at the top of the window, and walk around on the floor where the cameras can see your whole body.
  Your motion will be captured and the positions of your joints will be used to find the cameras relative positions.

After all cameras' extrinsic parameters calibrated, click the Find Ground button at the top of the window and walk around in the same way as If the marker cannot be read properly described below. This will determine the absolute position of the cameras.

If the marker cannot be read properly

Method to place marker on the wall

Since the position of the marker will be the plane with zero height of the captured motion, it is basically recommended to place the marker on the floor, but it may be difficult to read the marker on the floor depending on the placement and specification of the camera.

In that case, you can hang the marker on the wall to calibrate the camera and adjust the floor level later as follows:

• Replace the word "on the floor" with "on the wall" and execute the calibration procedure.
• Select GPU_DirectML in Settings > General > Run DNN on if your hardware support it. (If you have already installed the GPU_TensorRT mode in the Appendix, you can also use it.）
  Select Speed in Settings > General > Capture body if your PC's performance is enough for it. (If you have already installed the Precision mode in the Appendix, you can also use it.）
• Click the Find Ground button at the top of the window and walk around where at least 2 cameras can see your whole body. After a while, the position of the floor level will be adjusted automatically.

Confirm the results

If you have input the correct marker size in Prepare markers section, you can see the position of the camera in the 3D viewport.
Use the WASD key and mouse drag to move the viewport on MocapForAll.

Cameras may appear below the floor

In this case, the calibration has failed.

Save and load the results

For each camera

After calibration is completed, save the calibration result of each camera by clicking Save under Camera > Calibration > Intrinsic and Extrinsic. The saved result can be loaded by clicking Load button.

For all cameras

You can save and load the whole camera setup by clicking Save All Cameras and Load All Cameras buttons.

Caution when saving all camera settings

The camera selection is saved as the index inside the combo box. If you remove cameras from your PC, the order of the cameras in the combo box will change and you will not be able to load the cameras properly.