Rainfall Flow Simulation

2025

Overview

This gif shows rainfall as a simulation of angled particle motion, where each raindrop follows a calculated trajectory determined by trigonometric expressions. The direction of the rain is set by an angle of 80 degrees, and each drop's movement includes a horizontal displacement defined by cos(80°), which is approximately 0.1736. This small cosine value ensures the rain appears mostly vertical with a slight slant, mimicking natural rainfall influenced by wind.

The visual trail of each raindrop is computed using this same angular offset. The endpoint is found by extending the drop's origin horizontally by length × cos(80°) and vertically by its full length. This forms an angled segment where the x-component remains small due to the shallow cosine, while the y-component dominates, reinforcing the impression of diagonal rainfall across the scene.

The rate at which drops fall also incorporates numerical reasoning. The velocity of each drop is determined by 70 / s, where s is a speed scale ranging from 1 to 3. These discrete values control how far the raindrop travels per frame while still conforming to the angle-based path defined earlier, maintaining visual consistency within the animated system.