Glass somewhere behaves like glass and somewhere not ?

Support Materials and Textures
1

Hi,
I have scene where:

glass somewhere behaves like glass and somewhere not ??

here you can see render from living room and tech showers

What’s wrong. Any ideas please?

file here

2

Not sure what the problem is ! Explain !

3

glass shader is really not glass. its a glorified refraction shader with a splash of reflection. flat planes of glass have very little distortion, so you dont need refraction. just a transparent/glossy mix factored by a facing layer weight(not fresnel bc of backface problem) should do.

for refraction shaders to work, they need two faces, both facing opposite of each other. the ray goes in one, and needs to leave the other one, or it will think its still inside glass.