This is a paid asset, but now you can download Realtime Object Preview (3D Object on UI) Free.
Detail this asset from Unity Store: Original Link
Realtime Object Preview (3D Object on UI) v1.0
There are many uses for Realtime Object Preview. For example, if you want to implement an in-game Editor for your users, you can show which object is selected, using this asset! You can use this asset too, if you have many objects in your game, but you don’t want to create a thumbnail for all of them by hand. All scripts are fully commented and can be changed to fit your needs. To use this script you just have to drop a prefab in your scene! It’s as simple as that! Watch the video below to get a better idea what this asset is all about! Video: https://youtu.be/4OAr1VIlSfw