There are very few things more hypnotic than watching an embroidery machine do its work. When watching my wife’s machine working on festive decoration, I thought about how I’d create something similar in Houdini. Turns out it isn’t too complicated once you’ve figured out how to make the stitches run into a certain direction.
We decided that for the sake of art directability (does that word exist?) we’d settle on a manual appropach of drawing guide splines in order to define the direction in which the individual stitches would run. Next we’d create tangents based on those splines which we then feed into a velocity volume. Another way to look at it is that this works pretty similar to what you’d do when combing hair or fur.
In this video we go over the basic setup and creating a single spline for each stitch. For rendering (get the final render setup on our Patreon) we added a background with a weave shader as well as created secondars spines that coil around our stitch splies, in order to give the impression of twistes yarn.