Clarify default output geometry of feature class

README.md

@@ -42,7 +42,7 @@ The *Solve Large OD Cost Matrix* tool can be used to solve a large [origin-desti
 - **Output Updated Origins** (Python: *Output_Updated_Origins*) - Path to the output feature class that will contain the updated origins, which may be spatially sorted and have added fields. The OriginOID field in the Output OD Lines Feature Class refers to the ObjectID of the Output Updated Origins and not the original input origins.
 - **Output Updated Destinations** (Python: *Output_Updated_Destinations*) - Path to the output feature class that will contain the updated destinations, which may be spatially sorted and have added fields. The DestinationOID field in the Output OD Lines Feature Class refers to the ObjectID of the Output Updated Destinations and not the original input destinations.
 - **Output OD Cost Matrix Format** (Python: *Output_Format*) - The desired output format for the OD Cost Matrix Lines. The available choices are:
-  - "Feature class" - A single, combined feature class. This option is the slowest to create and will likely fail for extremely large problems.
+  - "Feature class" - A single, combined feature class. This option is the slowest to create and will likely fail for extremely large problems. Note: For performance reasons, the feature class output does not generate line shapes; the geometry of the features in the output is null. If you want straight line shapes, find the config file, `od_config.py`, in the toolbox's root directory and change `"lineShapeType": arcpy.nax.LineShapeType.NoLine,` to `"lineShapeType": arcpy.nax.LineShapeType.StraightLine,`.
   - "CSV files" - A set of .csv files. Each file represents the OD Cost Matrix Lines output, without shape geometry, for a chunk of origins and a chunk of destinations, using the naming scheme `ODLines_O_#_#_D_#_#.csv`, where the `#` signs represent the ObjectID ranges of the origins and destinations in the chunk. If you have set a value for the Number of Destinations to Find for Each Origin parameter, you may find some output files using the naming scheme `ODLines_O_#_#.csv` because results from all destinations have been combined into one file.
   - "Apache Arrow files" - A set of Apache Arrow files. Each file represents the OD Cost Matrix Lines output, without shape geometry, for a chunk of origins and a chunk of destinations, using the naming scheme `ODLines_O_#_#_D_#_#.arrow`, where the `#` signs represent the ObjectID ranges of the origins and destinations in the chunk. If you have set a value for the Number of Destinations to Find for Each Origin parameter, you may find some output files using the naming scheme `ODLines_O_#_#.arrow` because results from all destinations have been combined into one file. This option is not available in versions of ArcGIS Pro prior to 2.9 and is not available if the network data source is a service.
 - **Output OD Lines Feature Class** (Python: *Output_OD_Lines_Feature_Class*) - Path to the output feature class that will contain the OD Cost Matrix Lines output computed by the tool if the Output OD Cost Matrix Format parameter value is "Feature class". The schema of this feature class is described in the [arcpy documentation](https://pro.arcgis.com/en/pro-app/latest/arcpy/network-analyst/origindestinationcostmatrix-output-data-types.htm#ESRI_SECTION1_9FF9489173C741DD95472F21B5AD8374). Note that the OriginOID and DestinationOID fields refer to the ObjectIDs of the Output Updated Origins and Output Updated Destinations feature classes and not the original input data.