North Orientation

North is only one of four parameters you must set to display shadows that accurately portray the real world.
• Geographic Orientation — Relationship of True North to the model.
• Geographic Location — Latitude and Longitude
• Time — Year, Month, Day, Hour and Minute
• UTC Offset — The difference between local time and the Coordinated Universal Time standard.

By default, the +Y solid green Axis is true north to the shadow engine.
However, the +Y Axis is no longer true north if you geo-locate the model via SketchUp’s Add Location.

I find the simplest, most direct approach to shadow analysis is to manually geo-locate the model.
Window > Model Info > Geo-location > Set Manual Location
• Build the model along the Default Axes.
• Install the Solar North plugin (SketchUp Pro only) if you haven’t already done so.
• Use the Solar North tools to set true north in relation to the model.