Deep Search is the second group in the General Settings rollout.
When enabled, if Smart Merge can’t find an archive file corresponding to the preview file you imported, it will automatically search in the subfolder and custom search path. If Prompt is enabled, it will ask you before starting the search.
In the above example, if the file bludot_buddy_dining_chair.zip is put in Library folder, by default, the script won’t load anything into 3ds Max if you import the file bludot_buddy_dining_chair.jpg, because it finds no matching archive in the current directory. But if Deep Search is enabled, Smart Merge will be able to find that archive file.
If you put the archive file in a completely different path, you can click the Select Folder button to set the Custom Search Path. For example, in the image below, I set the Custom Search Path to “E:/LIBRARY”.
If the script still can’t find the corresponding archive in the subfolder and Custom Search Path, it will ask if you want to manually select the path for it as shown below.
In most cases, Deep Search will work fine with no performance issues, even in folders containing many subfolders. If you have problems with this feature, make sure that the paths and filenames do not contain special characters, and at the same time make sure the path is not too long (Windows has a MAX_PATH limit of ~256 characters).