Switching from rudimentary game objects to production-ready assets
Adding Assets to your game
First, import your assets to your game. If your assets are already contained within a Unity package file, you can drag and drop the asset from your computer’s file system to the Project view. This will open the import package manager. You can check/un-check boxes to determine which files should be added to your project, then click Import to process. Once imported, you can move the asset files into your project’s folder structure to keep things organized.
Depending on how your assets compare to your prototype objects, you may be able to add the asset as a child object of your prototype (ie. 3D prototype to 3D asset) — just be sure to remove or deactivate the prototype’s Mesh Renderer. If moving from 3D to 2D, you will need to make additional updates — either re-creating the object entirely from the asset or removing and replacing any 3D components on the prototype with 2D components (such as Rigidbodies or Box Colliders). If switching from 3D to 2D with colliders, be sure to update your script(s) to use the 2D version of any collision methods (ie. OnTriggerEnter2D).
For each asset you add to the scene, you may need to review and adjust the size, speed, rotation, relative offsets, etc. until the different assets and objects fit well together. If you serialized these variables when creating your prototype, you can easily make adjustments in the Inspector and avoid making changes in your scripts.
But why prototype in the first place?
When building your own games, you may be eager to add cool assets at the start, so you can see them in action. I admit, it is very exciting to get a glimpse of how the finish product will look. However, I would recommend prototyping first with basic game objects, whenever possible. Working with bare-bones objects allows you to focus on functionality instead of complexity, removing extra potential sources for issues and errors. Get it working, improve from there.
Plus, with just a few adjustments, I could easily add an asset and keep the existing functionality. So, really — why not prototype?
