Creating and Saving Unity Prefabs

CreateAndSavePrefab.cs

/*
Unity C# Psudocode to show how to create a mesh, save it as an asset and then attach it to a prefab.

by Rob Lang https://www.youtube.com/roblang
*/

#if (UNITY_EDITOR)
using UnityEditor;
using UnityEngine;

public static class PrefabBuilder
{
    /// <summary>
    /// Creates and saves a mesh and prefab from the given mesh, material and name
    /// </summary>
    /// <param name="myMesh">The mesh you want attached to the prefab</param>
    /// <param name="myMaterial">The material that the mesh will be rendered with</param>
    /// <param name="name">The Unity and hard disc safe name for the prefab</param>
    /// <returns>A prefab game object. You must instantiate real game objects from this if you want to use it</returns>
    public static class PrefabBuilder
{
    /// <summary>
    /// Creates and saves a mesh and prefab from the given mesh, material and name
    /// </summary>
    /// <param name="myMesh">The mesh you want attached to the prefab</param>
    /// <param name="myMaterial">The material that the mesh will be rendered with</param>
    /// <param name="name">The Unity and hard disc safe name for the prefab</param>
    /// <returns>A prefab game object. You must instantiate real game objects from this if you want to use it</returns>
    public static GameObject CreatePrefabFrom(Mesh myMesh, Material myMaterial, string name)
    {
        AssetDatabase.CreateAsset(myMesh, $"{name}.asset"); // If mesh asset exists, overwrite. Otherwise create.

        // Try load the prefab
        var prefabPath = $"Resources/{name}.asset";
        var prefab = AssetDatabase.LoadAssetAtPath<GameObject>(prefabPath);
        if (prefab == null)
        {
            var instance = new GameObject($"{name}");
            instance.AddComponent<MeshFilter>().sharedMesh = myMesh;
            instance.AddComponent<MeshRenderer>().material = myMaterial;
            prefab = PrefabUtility.SaveAsPrefabAssetAndConnect(instance, prefabPath, InteractionMode.AutomatedAction);
            UnityEngine.Object.DestroyImmediate(instance);
        }

        return prefab; // Although a gameobject, this is just a prefab - you have to Instantiate new gameobjects from it if you want to use it
    }
}

#endif