We solve this by using what's called a bounding volume hierarchy or BVH.

我们通过使用所谓的边界体积层次结构或 BVH 来解决这个问题。

Using BVHs helps to solve which triangle a ray will hit first but doesn't fix the fact  that a single frame of animation requires over a hundred billion rays.

使用 BVH 有助于解决光线将首先击中哪个三角形的问题，但并不能解决单个动画帧需要超过 1000 亿条光线的事实。