A method for predefining an entryway at a virtual boundary of an XR space contained within a real environment includes: accessing a spatial mapping mesh (SMM) for the real environment, and a sealed space mesh (SSM) for the XR space; analyzing polygons in the SMM and SSM to identify first subsets representing vertical surfaces and virtual wall boundaries respectively; filtering the first subsets according to first criteria to yield second subsets; colliding polygons across the second subsets to yield a third subset of SSM polygons; defining groups of connected SSM polygons within the third subset; and selecting one group as defining the entryway. The defining of the entryway is carried out in advance of user interaction with any virtual elements in the XR environment.