Starting a Precompute

Only static geometry is considered by Unity’s precomputed lighting solutions. To begin the lighting precompute process we need at least one GameObject marked as ‘static’ in our scene. This can either be done individually, or by shift-selecting multiple GameObjects from the hierarchy panel.

From the Inspector panel, the Static checkbox can be selected (Inspector>Static). This will set all of the GameObject’s ‘static options’, or ‘flags’, including navigation and batching, to be static, which may not be desirable. For Precomputed Realtime GI, only 'Lightmap Static' needs to be checked.

For more fine-grained control, individual static options can be set from the drop-down list accessible to the right of the Static checkbox in the Inspector panel. Additionally, objects can also be set to Static in the Object area of the lighting window.

If your scene is set to Auto (Lighting>Scene>Auto), Unity’s lighting precompute will now begin automatically. Otherwise it will need to be started manually as described below.