Updating thread from C++ uchar*

In my Unity project (for Android) im reading a frame from the device camera, passing it to a C++ plugin (uses opencv) for processing and in another scene the processed image from the c++ plugin is rendered on a material texture to be shown on a sphere gameobject. i don't see that the texture is changing even though i verified all functions in the c# and c++ are called in the correct order.

In the scene there is a sphere with a material that uses a skybox/cubemap shader

My code is heavily based on this example by unity for reading texture pointer and updating it.:
https://github.com/Unity-Technologi...aster/PluginSource/source/RenderingPlugin.cpp

my project setup is this:

C++ plugin with exposed functions:
1. read a pointer of the texture that would be modified

Code (CSharp):

1. extern "C" void UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API
2. SetTextureFromUnity(void *textureHandle, int w, int h) {
3.     // update global variables:
4.     g_TextureHandle = textureHandle;
5.     g_TextureWidth = w;
6.     g_TextureHeight = h;
7. }

2. read camera frame

Code (CSharp):

1. static void ReadTexturePixels() {
2.     void *textureHandle = g_TextureHandle;
3.     int width = g_TextureWidth;
4.     int height = g_TextureHeight;
5.     if (!textureHandle) {
6.         LOGE("ModifyTexturePixels", "ModifyTexturePixels - textureHandle is null");
7.         return;
8.     }
9.     std::thread processingThread(
10.             [&]() {
11. /** For now this call just saves the frame in a class member in cv::Mat variable to be retrieved later*/
12.                 cameraReader.readImageFrame(
13.                         (uchar*)textureHandle, 4 * height * width, 4, height, width);
14.             }
15.     );
16.     processingThread.join();
17. }

3. apply image to the texture from step 1.

Code (CSharp):

1. extern "C" void UNITY_INTERFACE_API SetVrMapView() {
2.     void *textureHandle = g_TextureHandle;
3.     int width = g_TextureWidth;
4.     int height = g_TextureHeight;
5.     if (!textureHandle) {
6.         LOGE("SetVrMapView", "SetVrMapView - textureHandle is null");
7.         return;
8.     }
9.    uchar * textureDataPtr = cameraReader.getPanoramaImage();/* returns frame.data, where frame is cv::Mat*/
10.     s_CurrentAPI->EndModifyTexture(textureHandle, width, height, textureDataPtr);
11. }

and EndModifyTexture:

Code (CSharp):

1. void RenderAPI_OpenGLCoreES::EndModifyTexture(
2.         void* textureHandle, int textureWidth, int textureHeight,
3.         void* dataPtr) {
4.     GLuint gltex = (GLuint)(size_t)(textureHandle);
5.     // Update texture data, and free the memory buffer
6.     glBindTexture(GL_TEXTURE_2D, gltex);
7.     glTexSubImage2D(
8.             GL_TEXTURE_2D, 0, 0, 0,
9.             textureWidth, textureHeight, GL_RGBA, GL_UNSIGNED_BYTE, dataPtr);
10. }

C# script:

Code (CSharp):

1.  
2. public class VrViewer : MonoBehaviour
3. {
4.     Texture writableTexture;
5.     [SerializeField] private Material screenImageFromPlugin;
6.  
7.     void Start()
8.     {
9.         Debug.Log("VrViewer  Start function");
10.         CreateWritableTexture(
11.             1080,
12.             2340);
13.         SetVrMapView(); // from C++
14.     }
15.  
16.     private void CreateWritableTexture(int width, int height)
17.     {
18.         Debug.Log("CreateWritableTexture " + width + " : " + height);
19.         writableTexture = new Texture2D(width, height, TextureFormat.RGBA32, false);
20.         SetTextureFromUnity(writableTexture.GetNativeTexturePtr(), writableTexture.width, writableTexture.height); // c++ function
21.     }
22.  
23. }