Stormvn 3D-CGi uses the Bifrost MPM Solver to create a procedural system to simulate curtains.

Stormvn 3D-CGi  (which used to be the HyUU channel) guided us through how he created a Bifrost simulation setup that can animate Curtains opening and closing.

The tutorial shows how to create a grid to manage the curtain rings and use the MPM Solver to drive the cloth simulation.

The setup also relies on caching the simulation, and Stormvn 3D-CGi shows you have some leeway to art directly in that regard.