Optimizing WebGL 4D Shaders for High-DPI Displays

Rendering real-time refractive glass and particle fluid simulations on modern Retina and 4K screens often results in GPU fillrate bottlenecks. Here is our mathematical approach to maintaining 60 FPS.

1. Resolution Downsampling & Bilateral Upscaling

Instead of rendering full-screen frosted glass passes at native devicePixelRatio (which can reach 3.0x on iPhone displays), we render heavy refraction buffers at 0.5x resolution and apply a bilateral blur filter before compositing back to the screen.

2. WebGPU Compute Shader Fallbacks

By offloading vertex noise computations to WebGPU Compute passes where supported, the CPU main thread remains 100% idle for smooth DOM scroll and UI animations.