Editor.RenderStaticPreview

Parameters

Returns

Texture2D Generated texture or null.

Description

Override this method if you want to render a static preview.

When overridden RenderStaticPreview can be used to render a list of assets converted into a single texture. This function will need user supplied source code that can merge the assets together. The size of the create texture can be supplied by the provided width and height.
If null is returned the builtin icon for the class type is used.

// Render the provided asset texture into an Inspector thumbnail.
using UnityEngine;
using System.Collections;
using UnityEditor;

using System.IO;

[CustomEditor(typeof(Example))]
public class ExampleEditor : UnityEditor.Editor
{
    public static void CreateAsset<Example>() where Example : ScriptableObject
    {
        Example asset = ScriptableObject.CreateInstance<Example>();

        string path = AssetDatabase.GetAssetPath(Selection.activeObject);

        if (path == "")
        {
            path = "Assets";
        }
        else if (Path.GetExtension(path) != "")
        {
            path = path.Replace(Path.GetFileName(AssetDatabase.GetAssetPath(Selection.activeObject)), "");
        }

        string assetPathAndName = AssetDatabase.GenerateUniqueAssetPath(path + "/New " + typeof(Example).ToString() + ".asset");

        AssetDatabase.CreateAsset(asset, assetPathAndName);
        AssetDatabase.SaveAssets();
        AssetDatabase.Refresh();
        EditorUtility.FocusProjectWindow();
        Selection.activeObject = asset;
    }

    [MenuItem("Examples/RenderStaticPreview example")]
    public static void CreateAsset()
    {
        CreateAsset<Example>();
    }

    public override void OnInspectorGUI()
    {
        Example e = (Example)target;

        EditorGUI.BeginChangeCheck();

        // Example has a single arg called PreviewIcon which is a Texture2D
        e.PreviewIcon = (Texture2D)
                EditorGUILayout.ObjectField(
                    "Thumbnail",                    // string
                    e.PreviewIcon,                  // Texture2D
                    typeof(Texture2D),              // Texture2D object, of course
                    false                           // allowSceneObjects
                );

        if (EditorGUI.EndChangeCheck())
        {
            EditorUtility.SetDirty(e);
            AssetDatabase.SaveAssets();
            Repaint();
        }
    }

    public override Texture2D RenderStaticPreview(string assetPath, Object[] subAssets, int width, int height)
    {
        Example example = (Example)target;

        if (example == null || example.PreviewIcon == null)
            return null;

        // example.PreviewIcon must be a supported format: ARGB32, RGBA32, RGB24,
        // Alpha8 or one of float formats
        Texture2D tex = new Texture2D (width, height);
        EditorUtility.CopySerialized (example.PreviewIcon, tex);

        return tex;
    }
}

ScriptableObject defining the PreviewIcon:

using UnityEngine;
using System.Collections;

public class Example : ScriptableObject
{
#if UNITY_EDITOR
    public Texture2D PreviewIcon;
#endif
}