1. A graphical processing system comprising: a rendering engine configured to receive a stream of graphics primitives, generate a plurality of sample positions in a two-dimensional field, compute depth values and color values for sample positions interior to the graphics primitives, and assign blur values to the interior sample positions based on the depth values and a concentration depth of a viewer; a sample buffer configured to store the blur values and the color values for the interior sample positions of the graphics primitives; a filtering engine configured to read the blur values and the color values corresponding to sample positions in a neighborhood of a current filter center, assign filter coefficients to the sample positions of the neighborhood based on positional measures of the sample positions with respect to the filter center and the corresponding blur values, multiply the color values of the neighborhood by the assigned filter coefficients to generate weighted color values, compute a pixel value based on the weighed color values; wherein the pixel value is usable to modify the state of a display device.