Calibration process

[Hoon mini]

Can Opencap software capture images simultaneously in the sagittal and frontal planes using two computers(Each camera up to 2)? If this is done, is it necessary to align the origin of the checkerboard during the calibration process? If alignment is required, is it possible to align the origins of two checkerboards?

[Scott Uhlrich]

You can capture sagittal and frontal plane by orienting the checkerboard 45 degrees from the frontal plane. both cameras will be able to see it in that case.

[Hoon mini]

"I plan to validate OpenCap in comparison with motion capture. It is recommended to rotate the checkerboard by 45 degrees for calibration to measure both the sagittal and frontal planes. In that case, how should I align the global coordinate system of motion capture with the origin coordinates in OpenCap?"

[Antoine Falisse]

OpenCap measures both frontal and saggital planes. Please take a look at our best practices here: https://www.opencap.ai/best-practices. You do not necessarily need to rotate the checkerboard.

To align the two systems, we recommend positioning a marker at the origin of the checkerboard (top left black-to-black corner) and align the checkerboard with eg force plates. That way you should be able to align both system during post-processing.

Hope it helps,
Antoine

[Hoon mini]

I always feel grateful for your hard work.