Rain on Umbrella
Looking up through a translucent umbrella at city lights, with refractive drops sliding down the dome and a slow walking drift.
What is Rain on Umbrella?
Rain on Umbrella is a free WebGL web effect in the TappyPrism library. Looking up through a translucent umbrella at city lights, with refractive drops sliding down the dome and a slow walking drift. It is rendered on the GPU by a fragment shader, so it costs almost nothing on the CPU and works well as a full-screen background. It ships as a single self-contained HTML file (rain-umbrella.html) with zero dependencies — no npm package, no framework, no build step. It exposes 3 live parameters — Rain Amount, Refraction Strength, Walk Speed — adjustable in the browser or at runtime.
Parameters
| Parameter | Key | Range | Default |
|---|---|---|---|
| Rain Amount | RAIN_AMOUNT | 0.1 – 2 | 1 |
| Refraction Strength | REFRACTION | 0.1 – 3 | 1 |
| Walk Speed | WALK_SPEED | 0 – 3 | 1 |
How to add Rain on Umbrella to your page
- Download the standalone file rain-umbrella.html and copy its source into your project.
- Or embed it as a background iframe:
<iframe src="https://prism.tappypotato.com/fx/rain-umbrella.html" style="position:fixed;inset:0;width:100%;height:100%;border:0;z-index:-1" title="Rain on Umbrella"></iframe> - Tune it at runtime with postMessage:
iframe.contentWindow.postMessage({ type: 'param', name: 'RAIN_AMOUNT', value: 1 }, '*');
Frequently asked questions
What is Rain on Umbrella?
Rain on Umbrella is a free WebGL web effect in the TappyPrism library. Looking up through a translucent umbrella at city lights, with refractive drops sliding down the dome and a slow walking drift. It is rendered on the GPU by a fragment shader, so it costs almost nothing on the CPU and works well as a full-screen background. It ships as a single self-contained HTML file (rain-umbrella.html) with zero dependencies — no npm package, no framework, no build step. It exposes 3 live parameters — Rain Amount, Refraction Strength, Walk Speed — adjustable in the browser or at runtime.
How do I add Rain on Umbrella to my website?
Download the standalone file at https://prism.tappypotato.com/fx/rain-umbrella.html and copy its source into your page, or embed it as a background iframe: <iframe src="https://prism.tappypotato.com/fx/rain-umbrella.html" style="position:fixed;inset:0;width:100%;height:100%;border:0;z-index:-1" title="Rain on Umbrella"></iframe>. Tune it live with postMessage, e.g. iframe.contentWindow.postMessage({ type: 'param', name: 'RAIN_AMOUNT', value: 1 }, '*').