Take a look at why the trace depth is important when dealing with transparent objects that use the arch&design material. Also see how to write a script that will change the trace depth value for multiple objects at once.
See why the trace depth is important in a scene where many objects are transparent. Learn where the trace depth can be adjusted globally and in the Arch & Design material. This is an important trick since you may encounter black spots in transparent objects and this is going to tell you why.
After you have realized what is described in the first section, you may need to change all materials in a scene and you don't know where to start. In this video, learn how to use max script to change a property of the Arch & Design material either it is used as a single material per object or inside a multi-sub material.