We present a new 3D particle tracking technique termed Individualized Defocusing Particle Tracking (IDPT), which uses intrinsic aberrations in standard laboratory microscopes to achieve dense, pointwise surface measurements at camera frame rates. IDPT combines calibration and 3D localization into an individualized tracking approach by leveraging the unique defocusing patterns of individual particles. We validated the performance of IDPT by separately performing 3D particle tracking on a planar substrate and on elastic discs.