1. A concise explanation of the problem you're experiencing.
I want to change the zoom step length, eg: when my mouse wheel scroll once, camera's height minus 100km.
Is there a way to modify the step size of the scroll wheel? mouse wheel scroll once, camera's height minus 50km. I watched the Cesium.ScreenSpaceCameraController class, but there seems to be no way to change this.
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.
4. The Cesium version you're using, your operating system and browser.