The light source directed in the plan is placed in the desired position and angle.
Location of the Directioanl Light Command
You can access it under the ribbon menu Rendering tab, Light - Camera title.
Click the Directional Light icon.
Click the point where you want to define the directional light with the left mouse button.
Move the mouse to rotate the light source in the direction you want.
When it is in the direction you want, click the left mouse button.
The light source will settle.
Determining the spot where the directional light will be placed
Determining the direction of the directional light
The formation of directional light