How Inside 3D Works
Inside 3D creates a table indicating which features fall within which closed multipatch features. All Input Features must have z information stored as part of their geometry. Additionally, the Input Multipatch Features should be closed. You can check if multipatch features are closed using the Is Closed 3D geoprocessing tool. If a multipatch feature is not closed, it will simply be skipped, and an error message displayed. In simple mode, a record is written out out for each feature in the fire input feature class or layer indicating if it falls inside, or partially inside any closed multipatch feature in the second feature class or layer. However, it may be the case that a single feature falls inside multiple closed multipatches. If the Complex Output Table option is checked, then a record is created in the table for each of these relationships, recording the input feature's object identifier, the type of relationship (Inside or Partially Inside), and the object identifier of the closed multipatch it shares that relationship with. Thus a single Input Feature may have multiple records in the output table, if the Complex Output Table option is selected.