This image is done with one of the mesh tools. In the zip you'll find an image with the menu settings to recreate it.
A smoke-like figure I've done with the attractor 2d tool.
In this version you can capture an image by clicking the mouse instead of pressing the key "S". I think it´s more handy this way.
the zip contains no sketch at all :)
this is just some dummy footage we like to share.