Four orbiting emitters rendered off-screen, then bright-pass → separable Gaussian
blur → composite — a chain of Framebuffers. Drag the sliders while it
runs; the passes reallocate nothing and every binding is restored after each one.
The pipeline: scene → bright-pass (threshold) → N× horizontal + vertical blur at quarter resolution → additive composite with tone mapping. See the Framebuffer reference for the API used here.