静态与动态光照的区别及烘焙光照的必要性

Lighting all objects dynamically and drawing shadows from all sources dynamically creates a life-like and beautiful image in an offline renderer, but in real time it is impractical. Moreover, it is not always necessary. For example, there are scenes where light sources do not move or turn off at all, and objects in them are static — why draw lighting for them every frame? You can and should save on everything that does not change. For this purpose UNIGINE has the following modes for light sources:对所有物体实施动态光照并实时计算所有光源的阴影，虽然在离线渲染器中能创造逼真精美的画面，但在实时渲染中并不实用。况且这并非总是必要——例如某些场景中的光源完全不会移动或关闭，其中的物体也都是静态的，何必每帧都重新计算光照？对于不变的元素，完全可以也应该节省资源。为此UNIGINE为光源提供以下两种模式：

• Dynamic Lighting is a customizable solution that provides real-time lighting calculation. This advanced method provides very realistic lighting as it allows dynamic objects to be illuminated. The light sources themselves can be moved or changed in real time (e.g. turned on and off).动态光照（Dynamic Lighting）：可定制的实时光照计算方案。这种先进方法能提供高度真实的光照效果，支持对动态物体的实时照明。光源本身也可实时移动或改变状态（如开关灯）。
• Static (pre-calculated) lighting is an effective and useful solution for lighting relatively static scenes. It is also called baked lighting. It allows you to discard the most of lighting calculations, performing only simple texture checks during rendering. However, this method provides just a rough simulation of lighting for moving objects entering the scene, and sometimes lacks physical fidelity, which can be noticeable to the eye.静态光照（Static Lighting）：针对相对静态场景的高效照明方案，又称烘焙光照(baked lighting)。该模式可摒弃大部分光照计算，仅在渲染时执行简单的纹理查询。但缺点是对进入场景的动态物体只能进行粗略的光照模拟，有时会缺失物理精度导致肉眼可见的瑕疵。

The good news is that these two modes can be combined. By using static lighting, you can achieve higher quality without sacrificing performance.好消息是这两种模式可以结合使用。通过静态光照既能保证更高画质，又不会牺牲性能表现。