I know that this question has been asked a LOT of times before, but none of the answers suited me, so...
This is a mesh with glass material applied. And everything is perfect. I can see everything through clearly (just a UV Sphere behind mesh).
But when I add "liquid" inside, with the same glass material applied, it is not transparent.It is on the other hand transparent when i hide the cup, but when it is looked through the cup, it is not.
I would not like to reset blender to default, because I have startup file finely tweaked.