Rotate/zoom around selected element

Oftentimes when I'm debugging/inspecting something real close, it becomes hard to navigate the camera, since any rotation centered on the scene and any rotation will quickly drift the view away from the element I'm trying to inspect. It would be good if we could, e.g., select an element (vertex, face, etc.) and have the camera rotate/zoom around it instead, which would facilitate inspection. I don't know if Polyscope has such a feature yet, but I think it'll be super useful.

未指定任何文件、测试或入口点。首先追踪 Polyscope 的相机导航和选择行为，然后定义选择顶点、面或其他元素时应如何设置旋转和缩放中心，并验证近距离检查时中心仍保持在该元素上。