Hi guys,
I created a train scene. But now, after render, I have two problems.
The last four windows look like mirrows. But why? It’s only the Glass Shader. Same Material like the other window
My image of the map is black. It only a Pricipled BSDF with an Image Texture. In Render View, it looks ok.
HELP 
Have you got any clamping enabled in your render panel? Your scene looks quite muted.
How many bounces have you got set too. For glass, you need to make sure you have adequate number of transparent bounces enabled.
Ok, to be hones, I don’t know what you mean 
My big glass has 30 Vertex and the small one 38
What would you improve?
Does the glass have thickness, or is it a single plane? If it’s a single plane, that would be problematic, because Cycles will calculate the glass as if it was infinitely thick and the outdoors were filled with solid glass.
Also, make sure the normals are pointing the correct way (the way the polygons are facing). Glass materials are affected by this and an inverted glass object will reflect and refract wrong.
For the map on wall.
I would like you to do a quick test that will narrow the problem down: try assigning the same material to an other object to see if it works correctly. If it does, you will know the problem is with the object and not with the material. If it doesn’t work, the problem is likely the material.
It can be so easy. I tried another Material with an image inside and same problem. Then I moved it away from my wall and saw a black Plane behind. Deleted it…works…oh boy… many thanks again
