How to get resulting texture on render texture and reuse it?

[TabishAzam]

Hello
I am trying to do operation on multiple textures. The trick is to forward the output of a material to a render target, and then read the resulting texture on render texture and give it back to the material.
In CPP the code is this :

   

//TextureInBox have texture pair
UTexture2D* texture1 =texturesInBox[texturesInBox.Num()-1].Key;// = texturesInBox[0];
    UTexture2D* texture1_N = texturesInBox[texturesInBox.Num() - 1].Value;
    UTexture2D* texture2 = texture1;
    UTexture2D* texture2_N = texture1_N;

    dynamicMaterial->SetTextureParameterValue(TEXT("TextureB"), texture1);
    dynamicMaterial->SetTextureParameterValue(TEXT("TextureB_N"), texture1_N);

    for (int32 Index = 1; Index < texturesInBox.Num(); ++Index)
    {

      //RenderTarget is of type URenderTarget2D
        texture1 = (UTexture2D*)renderTarget;
        texture1_N = (UTexture2D*)renderTarget_n;

        texture2 = texturesInBox[Index].Key;
        texture2_N = texturesInBox[Index].Value;

        dynamicMaterial->SetTextureParameterValue(TEXT("TextureA"), texture2);
        dynamicMaterial->SetTextureParameterValue(TEXT("TextureA_N"), texture2_N);

        dynamicMaterial->SetTextureParameterValue(TEXT("TextureB"), texture1);
        dynamicMaterial->SetTextureParameterValue(TEXT("TextureB_N"), texture1_N);



        this->EventTarget(dynamicMaterial,renderTarget);
        renderTarget->UpdateResourceImmediate(false);
    }

    dynamicMaterial->SetTextureParameterValue(TEXT("TextureA"), texture2);
    dynamicMaterial->SetTextureParameterValue(TEXT("TextureA_N"), texture2_N);

Part A of the solution is working : I can see material being drawn to render texture (BP attached)

Part B of the solution is to get the output displayed in renderTarget and use it again in the material
The issue is that, renderTarget is not returning the computed texture (a+b); it only shows the texture it was initialized with.

This is my Blueprint

Any help?