This effect is used for the power meter in Tower Topplers, a puzzle VS game I’ve been working on for the past year. It was created in Unity 2020.2.7 URP using the shuriken particle system and shader graph for some particle shaders. This shows the meter in its fully charged state. When each segment is fully charged it glows bright and an aura particle effect is enabled to clearly show the player how many segments they have available to use.
Each aura effect is composed of three particle systems that emit particles from a line and draw an emissive trail behind themselves. The idea here was to create something that looked chaotic and volatile, like the energy from the power gauge was barely being contained. I had a few goals I had to meet to achieve this look. First, I wanted it to look like one connected energy flow, not a bunch of separate particles. This meant that the base of the trail had to be fat so that the trails would connect to each other seamlessly. This goal is also what led me to use three separate line emitters per aura instead of one circle emitter. With one circle emitter I would commonly have situations where the random distribution would leave an area without particles and destroy the illusion that this was one connected effect.
My second goal was to make the aura feel unpredictable and electric. I accomplished this by having the trail shrink out of existence towards the end of its life. This creates spiky peaks and variations in the thickness of the aura that make the aura feel like its brimming with power. Combining this goal with the first goal was a tricky endeavor at first, I just couldn’t find width over trail curve that gave me the shape I needed. I solved this by having the trails inherit the size of the particles and using the particles size over lifetime curve to help craft the trail I was looking for. I used the width over trail curve to create fat trails that looked like malformed turnips, and then shrank the particle size over lifetime so that the trails would shrink over time and create the variation and thin peaks that i was looking for.
For context, this is what the effect looks like when paired with the rest of the UI.