All individual particles have a rotation value as one of their properties. I have decided to call this polarization. Particle rotation in OE-Cake has some unusual effects. Basic particle physics does not seem to be hugely affected by whether particles are rotated or not. Most materials have no special rotation behavior - Water particles are always polarized straight up and down and never rotate. Rigid particles rotate as a solid. Mochi, Tensile, and Powder particles are always polarized straight up and down. For this reason I believe most particle interaction does not take in to account rotation. Particles can rotate in response to an external force, or rotate continuously at a fixed rate. Rotation has no friction or momentum.
String particles behave as a solid but do not pay attention to rotation, even when connected to other particles such as Rigid. String is always polarized in the direction it was created, except when connected to Elastic, then each particle will follow the rotation of the Elastic particle it is connected to. If String is created from particles with a 45 degree rotation (for example, using Bucket to convert a rotated Rigid block) the particles will always maintain that orientation no matter what.
Elastic depends on each particle being polarized in the same direction, if connected particles have different rotations the spin-charged Elastic glitch happens. The net rotation of each particle will be infinitely added into the solid causing it rotate under it's own power. This infinite force could be used to power creations.
Viscous particles rotate relative to their direction of flow, as if they were tumbling. When Viscous glitches out, the particles rotate more and more intensely until they go nova. Viscous is able to "touch" String particles and cause them to rotate. Under certain circumstances Viscous can start a particle rotating and not stop it, causing the particle to rotate freely forever. The material String + Viscous is highly unusual, the particles seem to rotate relative to the forces applied, and then stay there. Perhaps SV could be used as some kind of memory material? Now I'm wondering if electrical conduction is affected by rotation.