Planes prepared for the GPU carry their depth of field (padding, radius map, levels) and the
bokeh_boost / bokeh_prefix / bokeh_gather kernels blur them where they are drawn, with the CPU's
spans; GPU-vs-CPU agreement tests for iris shapes, highlights, fringe, Fast Rectangle, tilted
planes and a 2D layer with a 3D track matte.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
