Accessing vertex data from a MTKVi… | Apple Developer Forums

I am drawing am image in a MTKView using a Metal shader based on the 'pointCloudVertexShader' used in this sample code. The image can be moved with a 'dragGesture' in the MTKView, similarly to the 'MetalPointCloud' View in the sample Code.

I want to implement a 'UITapGestureRecognizer' that, when tapping in the MTKView returns the appropriate 'vecout' (from the 'pointCloudVertexShader') value for the given location (see code bellow).

// Calculate the vertex's world coordinates.
float xrw = ((int)pos.x - cameraIntrinsics[2][0]) * depth / cameraIntrinsics[0][0];
float yrw = ((int)pos.y - cameraIntrinsics[2][1]) * depth / cameraIntrinsics[1][1];
float4 xyzw = { xrw, yrw, depth, 1.f };

// Project the coordinates to the view.
float4 vecout = viewMatrix * xyzw;

The 'vecout' variable is computed in the metal vertex shader, it would be associated with a coloured pixel. My idea would be to use the 'didTap' method to evaluate the wanted pixel data (3D coordinates).

@objc func didTap(_ gesture: UITapGestureRecognizer){
    let location = gesture.location(in: mtkView)
    //Use the location to get the pixel value.
}

Is there any way to get this value directly from the MTKView?

Thanks in advance!

Accessing vertex data from a MTKView