Is it possible to create new VisGroups that will automatically appears when certain entities/textures are used? Like how if you add clip brushes or game logic for the first time new VisGroups in the "auto" tab pop up.
At the top of the FGD, you can define auto visgroup behavior - this includes sub-groups as well, and what entities will be placed in them by default. Just create a new catagory of this format to set up a custom auto visgroup
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