The archive includes:
Fits perfectly into the interior. Also, the material of this curtain can be used with other curtain models from my profile.
Bathtub from preview: https://www.cgtrader.com/3d-models/interior/bathroom/acrylic-bathtub-pool-spa-windsor-180x85-cm
Polygons 62 809, Vertices 63 377 for each curtain.
Who works in 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