多光源实时全局光照算法的实现

针对全局光照尤其是多光源的全局光照的复杂性使其一直局限于离线应用的问题。对能量大的能代表多个光源的主光源，采用立即辐射度的方法，跟踪其光线产生虚拟点光源（VPLs：VirtualPointLights），这些VPLs再照亮场景实现实时的一次反射的间接光照。对场景中其他非主光源采用预计算光照图的方式计算其直接光照，动态主光源的直接光照及其间接光照与预算的光照图结合。在牺牲少许渲染质量的前提下，用CPU（CentralProcessingUnit）预计算光照图，GPU（GraphicsProcessingUnit）计算间接光照，并结合光照图合成最后的图像，实现了动态主光源、动态摄像机的多光源场景全局光照交互级绘制。

Realization of Many-Light Real-Time Global Illumination

The complexity of many-light global illumination has been limiting its use only to off-line applica- tions. We firstly approximates many light by a single brighter light, and the light paths are traced from this rep- resentative light, and VPLs （Virtual Point Lights） are generate at the vertices of these paths. Then, those VPLs are used to illuminating the scene, thus single-bounce indirect illumination can be rendered on currently availa- ble graphics hardware at real time rates. The direct illumination of other lights are pre-computed and stored in lightmaps, the contribution of dynamic lights and the resulting indirect illumination from that are computed and then combined with the lightmaps. At last, with little sacrifices in quality, the rendering of global illumination of the many-lights scene with dynamic representative light and dynamic camera achieves interactive rates.