Enrichment sphere
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Enrichment spheres are a structural part of the Underground aesthetic in Portal 2. They can be made by creating a func_instance and setting the VMF filename to "instances/underground/test_dome_interior_01.vmf". See instance for more information. These spheres contain Old Aperture Science's Test Chambers. They are ONLY found in the Aperture Science Innovators and Aperture areas in Portal 2 (2011).
Note:Don't make the room too big otherwise the room can exceed the sphere!