I came up with a problem of flipping only one face of the texture horizontally on flags as shown below in the image. What I want to do is to make one (front) face of the flag stay as it is now, but I would like to flip the other (rear face) by 180 degrees. I tried playing with the scale factors in the mapping node, rotating that face etc. The problem is that I am aware of the potential solution to this problem by duplicating the face and flipping the normals, but it will just make my job a lot harder due to complexity of the model and a huge lag I am currently experiencing. I would have to repeat the process a lot of times too. Therefore I would like to do it via compositor. I made a composition as shown on the screenshot, but it doesn't work no matter how I make them and what factors I put in. Can anyone take a look at it please, and tell me if I am doing something wrong, or it just isn't possible to be achieved in this way.
Thank you very much in advance.