siftDown(arr, n, i);
下一代3系将推出M350 xDrive，取代现款M340i xDrive，同时还将新增i3 40 xDrive、i3 50 xDrive两款纯电车型。
。搜狗输入法下载对此有专业解读
并且这些发光像素可以自由控制，S26 Ultra 的防窥模式还拥有两个防窥膜永远无法达成的效果：
Regions with many nearby points keep subdividing. Regions with few or no points stay large. The tree adapts to the data: dense areas get fine-grained cells, sparse areas stay coarse. The split grid is predetermined (always at midpoints), but the tree only refines cells that need it. Sparse regions stay as single large nodes while dense regions subdivide deeply.