Stencil Buffer in OpenGL: Interactive 3D Scene

This repository contains the implementation of a 3D scene using the Stencil Buffer in OpenGL. The project features a tetrahedron with holes cut into its faces, a semi-transparent cylinder enclosed within a torus, and dynamic scene rotation controlled by a timer.

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Problem Statement

The objective of this project is to create a visually appealing 3D scene that demonstrates the use of stencil buffers for cutting holes in 3D objects and rendering semi-transparent objects inside them. The scene is dynamically animated with continuous rotation to showcase the features of OpenGL in real-time rendering.

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Features

1. Tetrahedron with Holes:

   • Holes are created using a stencil buffer to mask specific areas.
   • Accurate masking and rendering of complex cutouts.

2. Semi-Transparent Cylinder:

   • Rendered inside the tetrahedron and modeled as a torus.
   • Implements blending for semi-transparency effects.

3. Scene Animation:

   • Smooth rotation of the entire scene using a timer.
   • Adjustable rotation speed for real-time updates.

4. Use of OpenGL Libraries:

   • GLFW: Window and input handling.
   • GLAD: Loading OpenGL functions.
   • GLM: Matrix and vector calculations.

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Input and Output

Input:

• Predefined vertices and indices for the tetrahedron and torus.
• Libraries integrated into the project environment.

Output:

• A rendered 3D scene with a tetrahedron containing stencil-based holes.
• Semi-transparent torus inside the tetrahedron.
• Real-time rotation of the scene.

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Implementation Details

Development Environment:

• IDE: Microsoft Visual Studio 2022.
• Language: C++.
• Libraries: OpenGL, GLFW, GLAD, GLM.

Steps:

1. Environment Setup:

   • Install necessary libraries (GLFW, GLAD, GLM).
   • Configure Visual Studio to include paths and dependencies.

2. Scene Creation:

   • Define vertices and indices for the tetrahedron and torus.
   • Use stencil buffers to cut holes in the tetrahedron's faces.

3. Rendering:

   • Implement vertex and fragment shaders for rendering.
   • Use blending for semi-transparent effects on the torus.

4. Animation:

   • Update the scene's rotation angle in the main loop based on a timer.

5. Resource Management:

   • Clean up allocated resources after rendering.

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Example Code Snippets

Tetrahedron Setup:

float tetrahedronVertices[] = {
    1.0f,  1.0f,  1.0f,
   -1.0f, -1.0f,  1.0f,
   -1.0f,  1.0f, -1.0f,
    1.0f, -1.0f, -1.0f
};

unsigned int tetrahedronIndices[] = {
    0, 1, 2,
    0, 3, 1,
    0, 2, 3,
    1, 3, 2
};

Stencil Buffer Configuration:

glEnable(GL_STENCIL_TEST);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
glStencilFunc(GL_ALWAYS, 1, 0xFF);

Animation:

while (!glfwWindowShouldClose(window)) {
    angle += deltaTime * 50.0f; // 50 degrees per second
    if (angle > 360.0f) angle -= 360.0f;

    glm::mat4 rotation = glm::rotate(glm::mat4(1.0f), glm::radians(angle), glm::vec3(0.5f, 1.0f, 0.0f));
    glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(rotation));

    // Render scene...
}

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Requirements

• Environment: Visual Studio 2022.
• Dependencies:
  • GLFW for window management.
  • GLAD for loading OpenGL functions.
  • GLM for mathematical operations.
• OpenGL Version: 3.3 or higher.

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Usage

1. Clone the repository:

   git clone: https://github.com/Nissmoline/StencilTetrahedron

2. Open the project in Visual Studio 2022.

3. Build the solution:

   • Select Release configuration.
   • Build using Ctrl+Shift+B.

4. Run the program:

   • Executable will be located in x64/Release/StencilTetrahedron.exe.

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Results

• Visualization: A tetrahedron with stencil-based holes and a semi-transparent torus rotating smoothly inside.
• Performance: Real-time rendering achieved with no errors or performance drops.

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License

This project is open-source and available under the MIT License. For more details.