Parametric Roman Curtains and Arched Window

To edit the curtain, go to the line with the Line modifier and change the shape of the curtain using Vertex, Segments or SplineThe thickness and width of the curtain can be changed by going to the layer with the Sweep modifier in the parameter graph.

In export files (Obj / fbx), the curtain is converted to geometry

In the archive:Max 2014 (v-ray 3.60.03)FBX / OBJ / MAT (v-ray 3.60.03)

Who works in the V-Ray version lower than 3.1, be careful, in the materials in the BRDF section there is Microfaset GTR (GGX), if your version is older than 3.1, then the BRDF field will be empty. Choose Blinn, Phong or Ward - which is preferable for you