# Fast Flow

## Overview

The Fast Flow effect runs a hydraulic particle simulation and creates a mask from it.

## Parameters

<table><thead><tr><th width="199.7999267578125">Properties</th><th>Description</th></tr></thead><tbody><tr><td><strong>Iterations</strong></td><td>The number of iterations the simulation will run for.</td></tr><tr><td><strong>Velocity Threshold</strong></td><td>Particles with a velocity below this value will be eliminated.</td></tr><tr><td><strong>Rain Strength</strong></td><td>The number of rain particles dropped at the beginning of the simulation.</td></tr><tr><td><strong>Smoothness</strong></td><td>Smoothes the resulting mask.</td></tr><tr><td><strong>Flow Cutoff</strong></td><td>Eliminates all particles that fall under a certain amount of water.</td></tr><tr><td><strong>Flow Smoothness</strong></td><td>Blends in softer regions between individual streams.</td></tr></tbody></table>

## Results

<div><figure><img src="https://2837684122-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FM6zsxw2jbMYEZbKqEwpa%2Fuploads%2FZQ3XhFhDO2Xuc1lLwGOi%2Freference_effects_base.webp?alt=media&#x26;token=231bbbf1-25f7-4ffd-b3ee-8772efa06d27" alt=""><figcaption></figcaption></figure> <figure><img src="https://2837684122-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FM6zsxw2jbMYEZbKqEwpa%2Fuploads%2F4xQeYHV0EPDQkXS5urk5%2Freference_effects_fastflow_02.webp?alt=media&#x26;token=e9c27e48-41a2-429d-8d18-fe1d4c9dead2" alt=""><figcaption></figcaption></figure></div>