You can remove the materials in session by discarding them in the Material Browser.
Note:
Materials loaded in session remain in session even after closing editors. Any unsaved
modification will persist when user reopens the material or structure from database.
Before you begin: In Me > Preferences > Infrastructure > Material Definition > Material Browser, set the options of the Material Browser. See Interface.
From the Tools section of the action bar, click
Material Browser.
All the materials loaded in session are
automatically pinned.
To discard a material in session, right-click a material in the Material Browser and select Discard.
The thumbnail of the discarded material changes to a pixilated gray.
Note:
You can discard several materials at the same time.
To remove the discarded material, click Discard.
Warning:
You cannot discard a material in session that is already
applied to an object.