# Particle System - Twirl Effect

This effect uses a Particles/Unlit shader with a simple twirl texture for the base map and is animated via the Particle System. This adds a 4th layer of depth into the black hole creation, allowing you even more flexibility for customizing your unique black hole.



**Configuration**

It’s simply the built-in unity particle system. You can freely customize like any other particle system. But for those that are not really familiar with particle systems, here is a small overview of how this effect is made:

<table data-header-hidden><thead><tr><th width="196.4000244140625"></th><th></th></tr></thead><tbody><tr><td>Looping</td><td>Checked since we do not want to stop after duration is over</td></tr><tr><td>Delay</td><td>No delay, we start directly </td></tr><tr><td>Start Lifetime</td><td>Min and max lifetime in seconds (15-20 in the example)</td></tr><tr><td>Start Speed</td><td>No start speed since we do not want to animate anything here</td></tr><tr><td>Start Color</td><td><p>Random between 2 colors to give a bit more variety to the effect</p><p>Both colors have alpha of 30. Increase the alpha value to make the effect stand out more.</p></td></tr><tr><td>Emission</td><td><p>The example used a random value between 0.4 and 0.8.</p><p>This means every second 0.4 - 0.8 particles will be spawned.</p></td></tr><tr><td>Color over lifetime</td><td>Using a gradient that shortly increases the alpha from 0 to 80 and then slowly fades to 0 again. Increase the alpha value here to make the effect stand out more.</td></tr><tr><td>Size over lifetime</td><td>Simple linear descending curve: On start the particle has its full size and shrinks until it fades away completely.</td></tr><tr><td>Rotation over Lifetime</td><td>Random rotation over lifetime between the min and max specified values.</td></tr><tr><td>Renderer</td><td><p>Material: Twirl material with the properly attached texture. </p><p>Render Alignment: Local, so if you change the size of its parent GameObject the size of this effect will also be changed accordingly.</p></td></tr></tbody></table>



Example of a Twirl particle system including all previously described shaders and effects

<figure><img src="https://lh7-rt.googleusercontent.com/docsz/AD_4nXcOpzchaDwDuJOPMVWMDzyFxmL-vhR6NbYrvOM-apH9Gz-NJjxwLDFE38CYwz69zoohyJa_gVZytsFyDpMIz7ySyRchaDrOEtkmGDY0FxP2Jew03ZKcIhl28Wvwd3ENfxV9nQE44JXyq_8ZPurQJw7VTj2Y?key=sB4Jy9v0wu6ZUWHskCB-vQ" alt=""><figcaption></figcaption></figure>
