CV Stereo Calibrate (Circle Grid)

Estimates the relative pose (R, T) between two cameras - and both sets of intrinsics unless they are pinned - from matched asymmetric circle-grid views (cv2.stereoCalibrate). Feed an IMAGE BATCH of stereo pairs (left and right views of the SAME board poses, same order); each pair is circle-grid detected independently and skipped unless BOTH views find the full grid. The 'asymmetric (staggered)' layout is the default and the point of this node: a symmetric grid looks identical when rotated 180 degrees, so a tilted board seen by two cameras cannot be matched unambiguously - the staggered rows break that ambiguity, which is why asymmetric circle grids are the standard target for stereo rigs. Pre-calibrate each camera with 'Calibrate Camera (Circle Grid)' and feed BOTH K matrices here to PIN the intrinsics (CALIB_FIX_INTRINSIC - only R and T are then estimated, which is the recommended two-stage workflow); with one or neither K connected the intrinsics are estimated/refined here and any K you did pass is only an initial guess. Failure-tolerant: with fewer than 3 usable pairs returns found=false with identity R and zero T. Feed R, T, K, dist into 'cv2.stereoRectify' for rectification.