Hi I took a bit of a simplistic approach when they plymouth was not animated in xubuntu 11.04
First, I found out what file was doing the file calling:
file:///lib/plymouth/themes/xubuntu-logo/xubuntu-logo.script
I found it using catfish and searching for plymouth
I copied the image I wanted to change to the same folder and tried out two things that worked out:
- find out what was the png that the script was calling and change the name for my image name.
- changed the name of my image so that it was the same as the script. (re named the original to *.png.old) actually i just opened the image with sudo inkscape and modified it the way I wanted.
What I was about to do for this animated one was option b but for all the different pngs that are in the folder. For something simple like a slight modification from the original it should be easy. But your volcano might be a bit more complicated but easy to try out: and low risk since you are not modifying a script.
I used inkscape to see how each part would look and hid the different png layers.
I guess it goes without saying that the easiest way to do this is to run sudo inkscape in the file:///lib/plymouth/themes/xubuntu-logo/
folder, backup the images and modify them keeping the same name the images .
Hope it helps.