Certainly, as you become more of an expert in AR, you realize how important lighting is to augmented reality. It's so important that Google developed ARCore with light estimation built in, which is why we spent this entire chapter on the subject. First, we learned about the rendering process in a bit more depth; then, we covered 3D lighting, an essential bit of knowledge that we will need in order to understand the added complexity of lighting in AR. This led us to look at the way ARCore estimates the light levels or global light in an area by taking a closer look at Unity Cg/HLSL shaders and, more specifically, surface shaders. Finally, we implemented a simple but effective hack to track and estimate light direct in a scene, which we left the reader with to improve on in their own time.

Estimating the actual lighting conditions of the environment will be a major hurdle for AR to overcome. However, with the incredible advances in AI and Machine Learning, we will likely see some better solutions come out soon. We will take a closer look at how Machine Learning can assist AR in the next chapter.