Animated pleated curtains.
You can independently change the % overlap of the window with the curtain using the animation panel (frame scale) if it is not displayed then turn it on in Menu > Customize > Show UI > Show Track Bar. The file contains instructions for using animated objects.
You can adjust the transparency of the curtain with the Translucency parameter (the higher the parameter the more transparent the curtain).
There are 2 versions of pleated curtains in the model archive:
1. Animated model with the possibility of changing the closure.
2. Static model of pleated curtains with closure on 100% 80% 60% 40% 20% and a fully open curtain (image on the main preview).