Plug-in Directory Search Mechanism

In the current locale directory, in the 3ds Max install directory (for example 3dsmax\en-US\) is a file plugin.ini. This file contains a one-line entry for each plug-in search location. When 3ds Max begins execution it searches each path listed in this file looking for plug-in DLLs. When a plug-in DLL is found it is loaded. This system allows developers to store their plug-ins in whatever sub-directory structure they wish. The format for the plugin.ini file is:

[Directories]
DescriptiveText=SearchPath

Here's what a sample plugin.ini might look like:

[Directories]
Civil View Plugins=C:\Program Files\Autodesk\3ds Max 2017\stdplugs\(CivilViewIO)

These paths show up on the Customize > Plugin Manager dialog.

There is also a section for help URLs:

[Help]
Help Name=URL

These URLs show up under Help > Additional Help...

In the %USERPROFILE%\AppData\Local\Autodesk\3dsMax\[version]\ENU directory, there is a Plugin.Usersettings.ini file associated with the current user, with the same format as plugin.ini. These paths can be configured by the user under Customize > Configure System Paths > 3rd Party Plug-Ins.