70s trail effect

Hi there everyone,
Here I am once again with a noob question…

I trying to understand how to create a 70s effect with color trails, where each layer has a different color from a rainbow ramp. The goal is to have a number of stacked colorful layers following the first one with a delay (and not a motion blur)


I managed to create an approximative version using cache and cache select, and using a lookup and a ramp to change the color of each “layer”. (see capture and .toe).

rainbow-trail.toe (6.93 KB)

I’m sure there is a way to:

  • use a single rainbow ramp with each layer picking the right color
  • use another approach for the trail so I could manage the number of layers with a parameter and not by manually creating a cache select for each one of them.

I tried playing with a feedback loop but this not the kind of effect I’m looking for (or maybe I didn’t found the right setup). I think maybe using a texture 3D and a time machine could do the trick, but I didn’t found the solution yet…

Any idea on the best way to achieve this?

I decided to use another approach: geo and instancing,
and boom, I managed to get everything I needed in 5 minutes:

  • a color ramp to color everything
  • a parameter to change the number of “layers”
  • a parameter to adjust the delay

My error is to always think about TOP when dealing with 2D, where once again geo and render were the solution to all my problems… But still, if someone has a TOP approach to this problem I’m curious to see it.

I share with you the result, playing with the parameter can give some pretty funny stuff (try 500 layers and 5s delay in the first constant chop for a cool effect)

rainbow-trail-v2.toe (6.88 KB)