Camera Calibrator 2d 3d correspondances

Hi, i am trying to calibrate a camera-projector pair using the camera calibrator app in matlab. I am projecting the calibration pattern and taking images from different camera angles. I am also extracting the 2D positions of the calibration pattern on the projector and camera image. I calibrate the camera and obtain the intrinsic and extrinsic parameters. However i am not sure how to obtain the 2D-3D correspondences from the data i have available? could somebody lead me towards a solution? Thanks