Question AsyncGPUReadback w. ComputeShader in EditorWindow

I'm trying to figure out the proper setup to run compute shaders from an editor window, but I must clearly be doing something wrong. The current setup usually runs for like a minute before the new texture is created in the project. (128x128 res, Unity 2020.2.0f1c1)

Any hints on what is wrong with this setup?

Editor Window

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Rendering;
3. using UnityEditor;
4. using System.IO;
5.  
6. public class ComputeTest : EditorWindow
7. {
8.     private Texture2D m_Input;
9.     private Texture2D m_Output;
10.     private RenderTexture m_RenderTexture;
11.     private ComputeShader m_ComputeShader;
12.  
13.     private void OnGUI ()
14.     {
15.         m_ComputeShader = EditorGUILayout.ObjectField (new GUIContent ("Compute Shader"), m_ComputeShader, typeof (ComputeShader), false) as ComputeShader;
16.         m_Input = EditorGUILayout.ObjectField (new GUIContent ("Input Texture"), m_Input, typeof (Texture2D), false) as Texture2D;
17.         EditorGUILayout.Space ();
18.  
19.         if (GUILayout.Button ("Compute"))
20.         {
21.             if (m_Input == null)
22.             {
23.                 return;
24.             }
25.  
26.             int size = m_Input.width;
27.  
28.             m_Output = new Texture2D (size, size, TextureFormat.ARGB32, false);
29.             m_RenderTexture = new RenderTexture (size, size, 0, RenderTextureFormat.ARGB32)
30.             {
31.                 enableRandomWrite = true
32.             };
33.             m_RenderTexture.Create ();
34.  
35.             int kernel = m_ComputeShader.FindKernel ("CSMain");
36.             m_ComputeShader.SetTexture (kernel, "Input", m_Input);
37.             m_ComputeShader.SetTexture (kernel, "Output", m_RenderTexture);
38.  
39.             EditorUtility.DisplayProgressBar ("Compute", "Running Compute Shader", 0.5f);
40.  
41.             // Submit compute shader
42.             m_ComputeShader.Dispatch (kernel,size/8, size/8, 1);
43.             AsyncGPUReadback.Request (m_RenderTexture, 0, TextureFormat.ARGB32, OnCompleteReadback);
44.         }
45.     }
46.  
47.     private void OnCompleteReadback (AsyncGPUReadbackRequest request)
48.     {
49.         if (request.hasError)
50.         {
51.             Debug.Log ("GPU readback error detected.");
52.             return;
53.         }
54.  
55.         // Get output filepath
56.         string filePath = AssetDatabase.GetAssetPath (m_Input);
57.         string directory = Path.GetDirectoryName (filePath);
58.         string extension = Path.GetExtension (filePath);
59.         filePath = Path.Combine (directory, "Output" + extension);
60.  
61.         // Retrieve texture, save to disk
62.         m_Output.LoadRawTextureData (request.GetData<uint>());
63.         m_Output.Apply ();
64.  
65.         File.WriteAllBytes (filePath, ImageConversion.EncodeToTGA (m_Output));
66.         DestroyImmediate (m_Output);
67.  
68.         // Update asset database
69.         AssetDatabase.ImportAsset (filePath, ImportAssetOptions.ForceUpdate);
70.         AssetDatabase.Refresh ();
71.  
72.         EditorUtility.ClearProgressBar ();
73.     }
74.  
75.     [MenuItem ("Tools/ComputeTest")]
76.     private static void Open ()
77.     {
78.         GetWindow<ComputeTest> ().Show ();
79.     }
80. }

Compute Shader

Code (CSharp):

1. #pragma kernel CSMain
2.  
3. Texture2D<float4> Input;
4. RWTexture2D<float4> Output;
5.  
6. [numthreads(8,8,1)]
7. void CSMain (uint3 id : SV_DispatchThreadID)
8. {
9.     Output[id.xy] = 1.0f - Input[id.xy];
10. }

 

Seems like this was fixed since then, as it works fine now in Unity 2020.3.