2D Sprites : Slice multiple sprite sheets at once

Questions & Answers
1

I have about 150 sprite sheets I need to slice. Each should be split by grid into 64 x 64 cells. It is an task in the Sprite Editor, except for the fact I need to do this 150 times. Is there a way to shift+click multiple sprite sheets then slice all at once? I can’t seem to open the Sprite Editor with multiple sheets clicked.

2

Maybe this could help: https://answers.unity.com/questions/1113025/batch-operation-to-slice-sprites-in-editor.html?_ga=2.32794360.796740819.1577073889-1730206695.1568833357

3

EDIT: You can now download Multi-Sprite Editor on the Asset Store. Allowing you to use EVERY FEATURE of the Sprite Editor on MULTIPLE Sprites at once, the be-all end-all solution!

here’s an overhaul to the script…

Added a seperate window under the menu item for slicing

Can now auto slice a sprite ie “can cut out nothing but the sprite from dead space”

To slice a sprite select one or more in the asset hierarchy then click the slice button in the window

Can change the pivot for each sprite sliced

Can change the threshold ie “the max pixel opacity to check for when auto slicing”

Make sure to put this script in a folder called: Editor

using UnityEditor;
using System.Collections.Generic;
using UnityEngine;

public class SpriteSlicer : EditorWindow
{

    static float threshold = 1;
    static Vector2 pivot = new Vector2(0.5f, 0.5f);

    void OnGUI()
    {
        threshold = Mathf.Clamp(EditorGUILayout.FloatField("Threshold: ", threshold), 0, 1);
        pivot = EditorGUILayout.Vector2Field("Pivot: ", pivot);

        if (GUILayout.Button("Slice"))
        {
            Slice();
        }

        this.Repaint();
    }

    [MenuItem("Sprite Slicer/Open Slicer")]
    static void OpenSlicer()
    {
        EditorWindow.GetWindow(typeof(SpriteSlicer));
    }

    static void Slice()
    {  
        Object[] spriteSheets = Selection.GetFiltered<Texture2D>(SelectionMode.Assets);

        for (int z = 0; z < spriteSheets.Length; z++)
        {
            string path = AssetDatabase.GetAssetPath(spriteSheets[z]);
            TextureImporter ti = AssetImporter.GetAtPath(path) as TextureImporter;
            ti.isReadable = true;
            AssetDatabase.ImportAsset(path, ImportAssetOptions.ForceUpdate);

            if (ti.spriteImportMode != SpriteImportMode.Single)
                ti.spriteImportMode = SpriteImportMode.Single;

            ti.spriteImportMode = SpriteImportMode.Multiple;

            List<SpriteMetaData> newData = new List<SpriteMetaData>();

            Texture2D spriteSheet = spriteSheets[z] as Texture2D;

            int maxY = 0;
            int maxX = 0;

            int minY = spriteSheet.height;
            int minX = spriteSheet.width;

            for (int i = 0; i < spriteSheet.width; i++)
            {
                for (int j = spriteSheet.height; j >= 0; j--)
                {
                    if (spriteSheet.GetPixel(i, j).a >= threshold && j > maxY)
                        maxY = j;

                    if (spriteSheet.GetPixel(i, j).a >= threshold && j < minY)
                        minY = j;

                    if (spriteSheet.GetPixel(i, j).a >= threshold && i > maxX)
                        maxX = i;

                   if (spriteSheet.GetPixel(i, j).a >= threshold && i < minX)
                        minX = i;
                }
            }

            SpriteMetaData smd = new SpriteMetaData();
            smd.pivot = pivot;
            smd.alignment = 9;
            smd.name = spriteSheet.name;

            smd.rect = new Rect(minX, minY, (maxX - minX) + 1, (maxY - minY) + 1);

            newData.Add(smd);
            ti.spritesheet = newData.ToArray();
            AssetDatabase.ImportAsset(path, ImportAssetOptions.ForceUpdate);
        }
    }
}