EN/CityGML-Tutorial/chapter-2:-Building/LOD3.md

@@ -119,7 +119,7 @@ In order to make a conversion from Sketchup to CityGML 2.0 LOD3 using FME, the m
 
 - Parent (gml parent ID) - child elements (gml ID) are separated with underscore ( _ ) and elements from their ids with dash ( – ). For example, a layer "ws-1_d-1"  interprets to “doors belonging to wall surface 1". In case of doors or windows, the parent boundary surface should hold all the individual elements. For example, if a wall surface (ws-1) has 2 doors and 3 windows, then the 2 doors should be put in a layer named ws-1_d-1 and the 3 windows in a layer named ws-1_w-1.
 
-- BoundarySurface having openings must be a separate layer. Remaining BoundarySurfaces can be a single layer according to the above classification. For example, in the below image because Door d-1 and Window w-1 are openings of only one WallSurface (here ws-1), a separate layer for WallSurafce (ws-1) is created followed by creating ws-1_d-1 (to model Door opening for ws-1) and ws-1_w-1 (to model Window opening for ws-1) are created. Rest WallSurfaces are part of layer ws. Such classification will help to assign gml parent IDs and gml IDs to maintain the hierarchical relation between the Building object, its BoundarySurfaces and Openings.
+- BoundarySurface having openings must be a separate layer. Remaining BoundarySurfaces can be a single layer according to the above classification. For example, in the below image because Door d-1 and Window w-1 are openings of only one WallSurface (here ws-1), a separate layer for WallSurafce (ws-1) is created followed by creating ws-1_d-1 (to model Door opening for ws-1) and ws-1_w-1 (to model Window opening for ws-1). Remaining WallSurfaces are part of layer ws. Such classification will help to assign gml parent IDs and gml IDs to maintain the hierarchical relation between the Building object, its BoundarySurfaces and Openings.
 
 - All polygons must be classified to its respective SketchUp layers based on above classification.