Following a suggestion, here is my question. I’m trying to follow the new Blender tutorial from Andrew, the one about a realistic beer still. Mind I’m still very newbie at how to adjust materials and I answered my own question to the liquid darkening through the glass by fiddling with the Ray Visibility panel.
My problem is, one of the steps after adding the foam is adding a “beer lace” to the inside of the glass, like if the liquid moved a little and leaves some foam sliding from along the inner walls of the glass. Step by step I did what he did at the video:
-Downloading his texture
-Duplicating the inner “dry” side of the glass.
-Check the normals points inside.
-Mark a seam on the duplicate.
-Cylinder unwrap the duplicate.
-Adjust the vertex to prevent odd pinching and stretching of the texture until it fits.
Everything looks fine, but when I rendered to check out if the beer lace was showing correctly, I realized the texture can’t be seen “through the glass”, but if you rotate the view a little to see the glass from above, you can see that the texture is there and showing properly. I tried to swap the normals of the “dry inside” mesh but to no avail.
I even rendered the scene without the glass, just the liquid and the foam “floating” there and the beer lace texture is there, white and all (well a tad more gray than the opposite side of it if watched from above).
I’m at my wits’ end. The experience points that maybe I have some option in my Blender either toggled ON or OFF but I can’t pinpoint the location of that after messing with all the T and N options, tabs, properties. I’m not experienced enough to guess this 
Tried to append the glass mesh from Andrew’s .blend file and I get the same results, no texture visible through the glass, and it feels odd because you can see the foam and liquid, but they aren’t textures so I suppose they are not treated the same during rendering.
Well, the pics or it never happened. Hope you can help me before Monday because this was supposed to be a homework for the weekend, and I guess I’m failing badly at it since Friday’s night sob
Update: After fiddling with the properties I noticed the glitch. Apparently when I duplicated that part of the glass, it kept the Ray Visibility Transmission OFF from the glass material I made for the cup. I turned it on and now it displays. It feels awkward to don’t be able to find a solution in 2 days and then after 1 hour or so of posting this I find the solution by my own. My apologies.
