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:

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

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