Question by nicolasjulioflores · Feb 09, 2018 at 02:03 AM · camera

NullReferenceException: Converting Camera to RenderTexture to Texture2D

I am currently trying to convert a camera view to a RenderTexture to a Texture2D, so that I can later extract the pixels.

The issue that I am getting is that when I try to use the Texture2D.ReadPixels() method, I am getting a NullReferenceException on the camera.targetTexture.width.

The error that is thrown on the line:

 var image = new Texture2D(cam.targetTexture.width, cam.targetTexture.height);

I am currently using this function:

 private Texture2D RTImage(Camera cam)
     {
         // The Render Texture in RenderTexture.active is the one
         // that will be read by ReadPixels.
         //RenderTexture myRT = cam.targetTexture;
 
         //var currentRT = RenderTexture.active;
         RenderTexture.active = cam.targetTexture;
 
         // Render the camera's view.
         // cam.Render();
 
         // Make a new texture and read the active Render Texture into it.
         var image = new Texture2D(cam.targetTexture.width, cam.targetTexture.height);
         image.ReadPixels(new Rect(0, 0, cam.targetTexture.width, cam.targetTexture.height), 0, 0);
         image.Apply();
 
         // Replace the original active Render Texture.
         //RenderTexture.active = currentRT;
         return image;
     }

The lines calling it are:

 Texture2D image = RTImage(Data_camera);

Data_camera is instantiated here:

 public Camera Data_camera;

And I've checked that I've dragged the main camera into the slot in the inspector.

The actual error message from Unity is:

 NullReferenceException: Object reference not set to an instance of an object
 CameraTest.RTImage (UnityEngine.Camera cam) (at Assets/Scripts/CameraTest.cs:39)
 CameraTest.Update () (at Assets/Scripts/CameraTest.cs:16)

Any help is appreciated. Thank you!

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