Phosphor persistence shader can now be added to any preset

The phosphor persistence effect stopped being trapped inside one shader path when Hyllian detached it from crt-geom-deluxe and uploaded a dedicated preset called phosphor-persistence inside the crt folder of the official repo. The key change was simple to use and big in practice: the preset could be prepended to any other CRT shader, which meant RetroArch users did not have to tear apart a favorite chain just to add one more display characteristic.

That matters because phosphor persistence, also called Afterglow in some shaders, is a temporal CRT effect. It affects how motion lingers on screen, so screenshots miss the point even when the effect is working exactly as intended. Hyllian pointed to R-Type 3 on SNES, Thunder Force 3 on Genesis, and vector games as clear test cases, where the lingering tails are easy to see in motion and where the look comes closest to the old hardware behavior people are trying to recreate.

Hyllian also said the behavior had been checked on a real CRT TV and that crt-geom-deluxe parameters were tuned to match the tail size of the asteroids and comets in R-Type 3. In the same thread, hunterk said the first few seconds of the Super Mario Bros. 3 title crawl with a black background were used while making the related phosphor-trails shader, which fits the way these effects often show up most clearly on dark title screens and high-contrast motion. A later comment in the discussion added another practical detail: the decay from 1/255 to 0 can take more than six seconds, which explains why the trails can look stubbornly long if the image stays dark long enough.

The thread also placed the feature in a broader shader ecosystem that was already moving in the same direction. Phosphor persistence had previously appeared only in some shaders, including crt-geom-deluxe, crt-guest-advanced, and glow-trails, but the new preset made it portable. A June 27 Uborder shaders release for Uborder-v0.3.5 also mentioned phosphor-persistence presets and shaders and called them good for vector games, showing how quickly the effect moved from a niche implementation detail into something pack authors could reuse.

For RetroArch users who have spent hours balancing scanlines, blur, mask settings, and performance, the change is straightforward: phosphor persistence became a modular add-on instead of a preset-specific obstacle. That is what makes the update stick, because the effect now fits the way shader setups are actually built, one layer at a time.