Realistic Lighting for Interactive Applications Using Semi-Dynamic Light Maps

2020-12-01
Öztürk, Bekir
Akyüz, Ahmet Oğuz
Light mapping is a technique that works by precomputing the lighting of a scene to speed up expensive lighting calculations at run-time. It is a commonly employed technique for computer games, in particular mobile games, due to the difficulty of creating realistic lighting effects on low power devices. The primary drawback of this technique is that the scene state that is dependent on the precomputed data cannot be changed at run-time. This limitation of light mapping significantly decreases the interactability of applications that use light maps. In this paper, we present a method to remove some of these restrictions at the cost of additional texture memory and small CPU/GPU workload. This allows changing the color and intensity properties of selected light sources at run-time, while keeping the benefits of the light mapping technique. It also makes it possible to show or hide the selected objects without giving rise to shadow artifacts and illumination inconsistencies. Our algorithm computes the light maps separately for each light source. Regions shadowed by each semi-dynamic object are also captured and stored. These maps are later combined at run-time to correctly illuminate the scene. Despite the increase in the generation time of the precomputed data, the overhead of the method is low enough to make it useful in many real-time applications. This makes our method especially suitable for interactive computer games designed to run on mobile and low-end graphics processors.
Citation Formats
B. Öztürk and A. O. Akyüz, “Realistic Lighting for Interactive Applications Using Semi-Dynamic Light Maps,” pp. 421–452, 2020, Accessed: 00, 2021. [Online]. Available: http://link.springer.com/10.1007/s40869-020-00116-2.