Compute Shader SetTexture error

Hello,
I'm new to Compute Shaders, I want to write a compute shader that modifies the texture by applying the color overlay filter effect. I tested the formula in C# and it works, but I'm unable to test it in Compute Shader as I keep receiving errors when I try to set a texture.

The texture has read and write enabled.

These are the errors that I receive:
1. Attempting to bind Texture ID 1395 as UAV, the texture wasn't created with the UAV usage flag set!
UnityEngine.ComputeShader:SetTexture(Int32, String, Texture)

2. IndexOutOfRangeException: Invalid kernelIndex (0) passed, must be non-negative less than 1.
UnityEngine.ComputeShader.SetTexture (System.Int32 kernelIndex, System.String name, UnityEngine.Texture texture) (at <e98ed0368295432e8c11e52d6243ee11>:0)

If I set a render texture it works fine, but I want to set a texture instead of a render texture.

C#

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.UI;
5.  
6. public class Test : MonoBehaviour
7. {
8.     [SerializeField] Image output = null;
9.     [SerializeField] Texture texture = null;
10.  
11.     [SerializeField] Color overlay = Color.white;
12.     [SerializeField] ComputeShader compute = null;
13.  
14.     private Texture final;
15.  
16.     private int kernel;
17.  
18.     void Start()
19.     {
20.         kernel   = compute.FindKernel("CSMain");
21.  
22.         //final = new RenderTexture(image.sprite.texture.width, image.sprite.texture.height, 24);
23.         //final.enableRandomWrite = true;
24.         //final.Create();
25.     }
26.  
27.     void Update()
28.     {
29.         final = texture;
30.  
31.         compute.SetTexture(kernel, "Result", final);
32.         compute.SetVector("color", overlay);
33.         compute.Dispatch(kernel, output.sprite.texture.width / 8, output.sprite.texture.height / 8, 1);
34.  
35.         output.sprite = Sprite.Create(final as Texture2D, Rect.zero, Vector2.zero);
36.     }
37. }
38.  

Compute Shader

Code (CSharp):

1.  
2. #pragma kernel CSMain
3.  
4. RWTexture2D<float4> Result;
5. float3 color;
6.  
7. [numthreads(8, 8, 1)]
8. void CSMain(uint3 id : SV_DispatchThreadID)
9. {
10.     float r = Result[float2(id.x, id.y)].r > .5f ? 2.0f * Result[float2(id.x, id.y)].r * color.x : 1.0f - 2.0f * (1.0f - Result[float2(id.x, id.y)].r) * (1.0f - color.x);
11.     float g = Result[float2(id.x, id.y)].g > .5f ? 2.0f * Result[float2(id.x, id.y)].g * color.y : 1.0f - 2.0f * (1.0f - Result[float2(id.x, id.y)].g) * (1.0f - color.y);
12.     float b = Result[float2(id.x, id.y)].b > .5f ? 2.0f * Result[float2(id.x, id.y)].b * color.z : 1.0f - 2.0f * (1.0f - Result[float2(id.x, id.y)].b) * (1.0f - color.z);
13.  
14.     Result[id.xy] = float4(r, g, b, 1.0);
15. }

 

So I modified the scripts and it works now.
The problem is that I still need to call readpixels and apply methods which are expensive.. :/

C#

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3.  
4. public class Test : MonoBehaviour
5. {
6.     [SerializeField] Image output = null;
7.     [SerializeField] Texture texture = null;
8.  
9.     [SerializeField] Color overlay = Color.white;
10.     [SerializeField] ComputeShader compute = null;
11.  
12.     private RenderTexture final;
13.     private Texture2D generated;
14.  
15.     private int kernel;
16.     private bool hasKernel = false;
17.     private Color applied = Color.white;
18.  
19.     void Start()
20.     {
21.         kernel   = compute.FindKernel("CSMain");
22.         hasKernel = compute.HasKernel("CSMain");
23.  
24.         generated = new Texture2D(texture.width, texture.height);
25.  
26.         final = new RenderTexture(texture.width, texture.height, 24)
27.         {
28.             enableRandomWrite = true
29.         };
30.         final.Create();
31.     }
32.  
33.     void Update()
34.     {
35.         if (!hasKernel) return;
36.  
37.         bool hasChanged = overlay != applied;
38.  
39.         compute.SetTexture(kernel, "Result", final);
40.         compute.SetTexture(kernel, "ImageInput", texture);
41.         compute.SetVector("color", overlay);
42.         compute.Dispatch(kernel, texture.width / 8, texture.height / 8, 1);      
43.  
44.         if (hasChanged)
45.         {
46.             RenderTexture.active = final;
47.  
48.             //Expensive part
49.             generated.ReadPixels(new Rect(0, 0, texture.width, texture.height), 0, 0);
50.             generated.Apply();
51.  
52.             output.sprite = Sprite.Create(generated, new Rect(0.0f, 0.0f, texture.width, texture.height), new Vector2(0.5f, 0.5f), 100.0f);
53.         }
54.  
55.         applied = overlay;
56.     }
57. }
58.  

CS

Code (CSharp):

1. // Each #kernel tells which function to compile; you can have many kernels
2. #pragma kernel CSMain
3.  
4. RWTexture2D<float4> Result;
5. Texture2D<float4> ImageInput;
6.  
7. float3 color;
8.  
9. [numthreads(8, 8, 1)]
10. void CSMain(uint3 id : SV_DispatchThreadID)
11. {
12.     float r = ImageInput[float2(id.x, id.y)].r > .5f ? 2.0f * ImageInput[float2(id.x, id.y)].r * color.x : 1.0f - 2.0f * (1.0f - ImageInput[float2(id.x, id.y)].r) * (1.0f - color.x);
13.     float g = ImageInput[float2(id.x, id.y)].g > .5f ? 2.0f * ImageInput[float2(id.x, id.y)].g * color.y : 1.0f - 2.0f * (1.0f - ImageInput[float2(id.x, id.y)].g) * (1.0f - color.y);
14.     float b = ImageInput[float2(id.x, id.y)].b > .5f ? 2.0f * ImageInput[float2(id.x, id.y)].b * color.z : 1.0f - 2.0f * (1.0f - ImageInput[float2(id.x, id.y)].b) * (1.0f - color.z);
15.  
16.     Result[id.xy] = float4(r, g, b, 1.0);
17.  
18. }