how to solve the Anti-aliasing Problem of 3D Model

1. A concise explanation of the problem you're experiencing.

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.

Check out some of the suggestions in this thread:

https://groups.google.com/d/msg/cesium-dev/XXXBFSYgb7s/SLZ0WokbCAAJ

Let me know if helps.