Indeed, VBE seems to lack the ability to show objects of varying transparencies. If a material has any transparency at all, once it goes to VBE, all transparent materials seem to get thrown into a pool and VBE shows them all as the same level of clear. Therefore it's almost impossible to show frosted glass vs clear glass. BUT there is a workaround (until graphisoft fixes this in the next update - please!). I found that creating .png images with varying transparency, and applying them as textures works fine. For example, I can go into photoshop, create a blue image with 50% transparency, save it as a .png file, load into my archicad library, and apply it as a texture to my frosted blue glass material in, and when I export to VBE, I get a 50% transparent blue piece of glass! You can do any degree of transparency from 0 to 100% in photoshop, and in any color. Obviously simple frosted glass should be done with white.