c++ - Why is my OpenGL application rendering a 3D model with unexpected transparency? - Stack Overflow

I'm developing a game engine using SFML for window management and OpenGL for rendering with C++. My goal is to render a 3D model, but parts of the model appear transparent. I've tried multiple approaches to ensure the model is rendered fully opaque, but the issue persists. As i rotate my camera around the model, the front faces are invisible. Due to this i always see the faces in the back.

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My setup (minimal):

Source files

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What I've Tried

• I disabled blending globally before rendering

  glDisable(GL_BLEND);
  

• I ensured the clear color has a fully opaque alpha value

  glClearColor(0.9f, 0.9f, 1.0f, 1.0f);
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  

• I ensured depth testing is enabled

  glEnable(GL_DEPTH_TEST);
  glDepthFunc(GL_LESS);
  

• I replaced the fragment shader with a simple solid color to isolate texture issues. The model still renders with transparency in some areas.

Question:

1. Why is the model rendering with transparency, even after disabling blending and ensuring opaque colors in the shader?