1. A concise explanation of the problem you’re experiencing.
I am using the api below
Cesium.Cartesian3.subtract(left, right, result)
just like other api,
the third parameters is “result”
but it is not optinal
the other api in cesium,the third parameters “result” mostly is optinal
why is this api not？
2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.
3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
I want all the cesium api keep the same style
4. The Cesium version you’re using, your operating system and browser.
1.61