Archicad users are well-advised to review material images found on the path in the attached image - as supplied by Graphisoft but not necessarily incorporated into materials yet.
Also please review material archives that come with Archicad - these derive their textures from images in folders also supplied and installed with Archicad. [Load Settings from Archive]
Four glass block images with transparency are at the attached location within Archicad awaiting you to add them to material shaders. Are these not satisfactory?
Dwight Atkinson