When Archicad subdivides material it creates long triangles that resemble a "broken mirror". Advanced rendering software packages like Thea Render and Maxwell require subdivided triangles or squares that have close to equal sides to accurately and efficiently generate displacement maps for materials.
It's not archicad's problem. The rendering engine is the one that should make the subdivision at rendertime. If it doesn't, then either you haven't learn how to use it or it has bugs.
For such textures you should use bump mapping, it's much faster and it looks the same.