How can I create an "afterimage" effect like this one?

Question

How can I make an effect like this? With a particle system?

Answer 1

• Create a new particle system
• In the general settings:
  • "Start Lifetime" reduce a lot. The lower, the lower the length of the particle trail. In my example I am using 0.2.
  • "Start Speed" to 0, so the particles don't move from where they were created.
  • "Simulation Space" to "World" so the particles don't move when the parent moves
• "Emission":
  • Controls the number of after-images in the trail. In my example I increased it to 100. Should be at least 5 / StartLifetime to avoid flickering.
• "Shape"
  • Uncheck this module, so all particles are spawned at exactly the position of the particle system
• In "Color over Lifetime":
  • set the gradient to fade from 255 alpha to 0 alpha so the trail-sprites fade out over time
• In Renderer
  • Create a new material with the shader "Particles/Alpha Blended"
  • Set the desired sprite as the sprite of that material
  • Assign that material to the Renderer
• Optional: Adjust start lifetime and emission amount to taste to control length and density of the trail.

Result when you move the object:

Answer 2

You can achieve this sort of effect pretty easily. You don't have to use a particle system to do so, but it can work pretty well. The structure is:

• You want a system that emits a single stationary particle (zero velocity) at a fixed interval.
• Configure the particle so that it decays over whatever period of time you want (this will be the time it takes each afterimage to "fade out"), and is spawned with whatever the current animation frame is.
• Tie the decay of the particle to it's opacity, so it gets more transparent as it approaches the end of its lifetime.