there are thin lines in clouds 云中有细线

My English is poor,so please read Chinese if possible.

The bug

When I watch clouds with a spyglass,I find that there are white thin lines in clouds（such as 1.png).

And there are also white spots when I watch without spyglasses.(such as 2.png and 3.png) 

It is similar to MC-261354 but whith spot don't move sometimes.

How to reproduce:{*}{*}

1. turn options-Video Settings-Clouds into Fancy.

2. Back to Game and watch clouds with/without a spyglass.

问题

当我使用望远镜观查云时，发现云中存在白色的细线(如图1）。在不使用望远镜看时也会有白点(如图2与3）。这与 MC-261354有些相似但有时白点不会动。

如何复现：

1. 将选项-视频设置-云改为高品质。

2. 回到游戏并使用/不使用望远镜看云。