Set orthographic camera viewport rect to capture all of the selected bounds.
Import to Your Project
You can import this asset from UnityPackage.
You have to import following assets to use this asset.
How to Use
BoundsCaptureCamera.cs to camera and set some Bounds which inherit
BoundsMonoBehaviour.cs in Inspector.
BoundsCaptureCamera.UpdateCaptureArea() method to
BoundsMonoBehaviour.BoundsUpdateEvent if you need.