A physics based 2D fluids modeling paint program, OE-Cake, has seen what must be its highest possible purpose – the realistic swaying, kneading and bouncing of 2D oppai, come true, thanks to the ever inventive (and oft debauched) minds of otaku.
Below are some demonstration videos of the program being applied to various 2D idols to create alluring scenes of bouncing oppai, as well as a video tutorial that might be of help to would-be oppai modelers.
Firstly, some examples of what a OE-Cake-like program is capable of:
This tutorial, accompanied by Engrish captions, demonstrates the use of the program:
The OE-Cake Wiki also offers some instruction, as well as download links, for this most useful program.