export sprite sheets

I know it's been a while since this was asked, but I just had a need for this myself, so...

You can extract all the sprites in a sprite sheet using Unity itself. Here are the steps I used:

1. make the imported sheet readable (settings -> debug view -> texture type: advanced)

2. move it into your Resources (so you can load it via code)

3. in script, load the sprite sheet:

          Sprite[] sheet = Resources.LoadAll<Sprite> (sheetName);
   
   

4. iterate over all the sprites, and extract each:

          foreach (Sprite sprite in sheet) {
                Texture2D tex = sprite.texture;
                Rect r = sprite.textureRect;
                Texture2D subtex = tex.CropTexture( (int)r.x, (int)r.y, (int)r.width, (int)r.height );
                byte[] data = subtex.EncodeToPNG();
                File.WriteAllBytes (Application.persistentDataPath + "/" + sprite.name + ".png", data);
            }
   
   

5. The extracted files will end up wherever the persistent path is - just debug it out so you know:

          Debug.Log(Application.persistentDataPath);
   
   

The CropTexture method is an extension method to the Texture2D class. Create the file "Texture2DExtensions.cs", and paste this in:

 using UnityEngine;
 using System.Collections;
 
 static class Texture2DExtensions
 {
     /**
      * CropTexture
      * 
      * Returns a new texture, composed of the specified cropped region.
      */
     public static Texture2D CropTexture(this Texture2D pSource, int left, int top, int width, int height)
     {
         if (left < 0) {
             width += left;
             left = 0;
         }
         if (top < 0) {
             height += top;
             top = 0;
         }
         if (left + width > pSource.width) {
             width = pSource.width - left;
         }
         if (top + height > pSource.height) {
             height = pSource.height - top;
         }
 
         if (width <= 0 || height <= 0) {
             return null;
         }
 
         Color[] aSourceColor = pSource.GetPixels(0);
 
         //*** Make New
         Texture2D oNewTex = new Texture2D(width, height, TextureFormat.RGBA32, false);
         
         //*** Make destination array
         int xLength = width * height;
         Color[] aColor = new Color[xLength];
 
         int i = 0;
         for (int y = 0; y < height; y++) {
             int sourceIndex = (y + top) * pSource.width + left;
             for ( int x = 0; x < width; x++ ) {
                 aColor[ i++ ] = aSourceColor[ sourceIndex++ ];
             }
         }
         
         //*** Set Pixels
         oNewTex.SetPixels(aColor);
         oNewTex.Apply();
         
         //*** Return
         return oNewTex;
     }
 }