To use an environment variable in one of the Arnold search paths, you just have to put the environment variable in square brackets [ ].

For example, [ARNOLD_PLUGINS_PATH] or [MY_TEXTURE_PATH].

A search path can include many paths; just use a semi-colon (;) to separate each path. For example, here’s a search path that includes three different locations:

[ARNOLD_PLUGINS_PATH];[USERPROFILE]\Dev\shaders\bin\Release\x64;[MY_PLUGINS_PATH]