Sprite Renderer Performance

We figured out hat this can be solved with http://docs.unity3d.com/Manual/class-RenderTexture.html.

However; with proper sorting; draw calls dramatically reduced to 2-3 calls; so we did not need id.

Edit: Later on we need it for some other performance enhancements :) here how the code looks like:

@SmashingSuccess here is the code:

 public class Photographer : MonoBehaviour
     {
         public Camera MasterCamera;
         public Camera SelfCamera;
         public SpriteRenderer BackgroundDisplayer;
 
         public LevelBuilder CurrentLevelBuilder;
         public LayerMask Layer1;
 
         public void TakeShot()
         {
             SelfCamera.transform.position = MasterCamera.transform.position;
             SelfCamera.orthographicSize = MasterCamera.orthographicSize;
 
             var w = SelfCamera.pixelWidth;
             var h = SelfCamera.pixelHeight;
 
 
             //Background
 
             SelfCamera.cullingMask = Layer1;
             var texture = new RenderTexture(w, h, 0, RenderTextureFormat.ARGB32);
             SelfCamera.targetTexture = texture;
             SelfCamera.Render();
 
             RenderTexture.active = texture;
 
             var textureFormat = TextureFormat.RGB24;
 
             //https://issuetracker.unity3d.com/issues/error-regarding-invalid-textureformat-when-calling-supportstextureformat
 #if UNITY_ANDROID
 // if (SystemInfo.SupportsTextureFormat(TextureFormat.ETC_RGB4))
 // {
 //    textureFormat = TextureFormat.ETC_RGB4;
 // }
 #elif UNIT_IOS
 // if (SystemInfo.SupportsTextureFormat(TextureFormat.PVRTC_RGB4))
 // {
 //    textureFormat = TextureFormat.PVRTC_RGB4;
 // }
 #endif
 
             var virtualPhoto = new Texture2D(w, h, textureFormat, false);
             virtualPhoto.name = "PhotoBackgroundTexture";
             var r = new Rect(0, 0, w, h);
             virtualPhoto.ReadPixels(r, 0, 0); // you get the center section
             virtualPhoto.Apply();
             var bg = Sprite.Create(virtualPhoto, r, new Vector2(0.5f, 0.5f), 100f);
             bg.name = "PhotoBackgroundSprite";
             RenderTexture.active = null;
             BackgroundDisplayer.sprite = bg;
 
             SelfCamera.targetTexture = null;
             Destroy(texture);
 
 
             var scaleNeeded = 100 * (MasterCamera.orthographicSize * 2) / h;
             BackgroundDisplayer.transform.localScale = new Vector3(scaleNeeded, scaleNeeded, scaleNeeded);
 
 
             SelfCamera.enabled = false;
             BackgroundDisplayer.enabled = true;
 
             MasterCamera.clearFlags = CameraClearFlags.SolidColor;
 
             var all = GameObject.FindGameObjectsWithTag("ToBePhotographed");
             for (var i = 0; i < all.Length; i++)
             {
                 Destroy(all[i]);
             }
             Destroy(gameObject);
         }
     }

SelfCamera is responsible to take screenshot. It only renders "Layer1". All other cameras; renders everything except "Layer1". Items who are going to be photographed are tagged with "ToBePhotographed" and are configured to be rendered in "Layer1". After screenshot is taken; they are destroyed..