Surely you have noticed that objects already appear to be illuminated when they are rendered. This is due to the presence of a Default light that is always present if no other light sources are present in the scene. The Default light’s position is linked to the position of the camera but can also be changed manually in the
The position of this otherwise invisible light source can be changed by clicking and dragging on the sphere. This lets you get a rough impression of how an object will look when lit from a different direction.
This light is, however, limited to the shading of the surface of objects and the creation of specular highlights - calculating a cast shadow or changing the light’s brightness or color are not possible. Furthermore, only a single Default light exists at any time and is therefore not suited for lighting an entire scene. If Global Illumination is enabled or if a light source is added to the scene, the Default light will automatically be turned off so it does not influence the illumination of the scene. The Default light can also be disabled manually via the Default Light option in the
A Light object must be created in order to correctly illuminate your scene, including shadow casting and other options. This