Combining several measurements in a time sequence leads to tracking and tracing. GPGPU can be used for many types of embarrassingly parallel tasks including ray tracing. This orderly pattern of depolarization gives rise to the characteristic ECG tracing. The design of procfs aimed to replace the "ptrace" system call used for process tracing. Weta utilized RenderMan to take advantage of improved ray tracing and instancing objects. Drawings were made on vellum, coated linen, and tracing paper. These bounds are based on similar complexity bounds obtained for ray tracing. Various complexity results have been proven for certain formulations of the ray tracing problem. An ECG tracing is affected by patient motion. The volume is available for sparse tracing of selected circuits. Warhol habitually used the expedient of tracing photographs projected with an epidiascope. This is a desirable quality for some applications such as ray tracing. Therefore, it is clearer to distinguish "eye-based" versus "light-based" ray tracing. This simultaneous contraction results in the P wave seen in an ECG tracing. It also defines a high speed auxiliary port interface, used for tracing and more.