Benefits and Costs

Although it is possible to simultaneously use Baked GI lighting and Precomputed Realtime GI, be wary that the performance cost of rendering both systems simultaneously is exactly the sum of them both. Not only do we have to store both sets of lightmaps in video memory, but we also pay the processing cost of decoding both in shaders.

The cases in which you may wish to choose one lighting method over another depend on the nature of your project and the performance capabilities of your intended hardware. For example, on mobile where video memory and processing power is more limited, it is likely that a Baked GI lighting approach would be more performant. On ‘standalone computers’ with dedicated graphics hardware, or recent games consoles, it is quite possible to use Precomputed Realtime GI or even to use both systems simultaneously.

The decision on which approach to take will have to be evaluated based on the nature of your particular project and desired target platform. Remember that when targeting a range of different hardware, that often it is the least performant which will determine which approach is needed.