I started this image one year ago, I just coming back on it ! I had the idea to test this scene with the Bidirectional Pathtracer method. Here’s the first results ( original final rendering 2K x 2K px, raw render):
Of course, I use Physics to make the blanket ( a simple subdivised plane). Blanket as a Cloth, seat as Collider and gravity do the rest. But I had some troubles to get good results ( the blanket was always in levitation above the seat, I’m not an expert in animation and Physics, it’s more a test for me).