I had to do a little debugging with the simple animations package because the PlasmaRenderer class was not recognized. Not sure if they got rid of it or renamed it in a newer version, but I have to bring my code version down from 5.0.0^ to 3.0.3^ in order to get it working.
The specific location of the bug is on this file, line 31
I will open an issue in the simple_animations repo to request better documentation, but I figure I'd open this one too to keep the demo fresh given I found it on Flutter Showcase.
Finally, thank you for making this! I am copying this fancy plasma code to use on my splash screen and appreciate the open-source work!