A simple 3D renderer from scratch

A minimalist 3D renderer implemented in C++ with almost zero external dependencies, running entirely on CPU. It implements its own rasterization, matrix transformations in 3D and shading techniques.

🚀 Quick Start with CMake

Requirements: CMake v3.16+, C++ v17+

git clone https://github.com/M1v1savva/mini-renderer.git
cd mini-renderer
mkdir build && cd build
cmake ..
make
cd ../output/
./mini-renderer --mode texp --path out.tga --config ../config.json

See out.tga

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Results

Given two files:

• *.obj (polygonal mesh)
• *.tga (texture)

The renderer is producing images like this:

Gouraud shading (no texture)

Phong shading (with texture)

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Features

• Z-buffering: depth handling for correct rendering order
• Transformations: camera view, projection, viewport; applied to lights too
• Rasterization: texture mapping, Gouraud and Phong shading
• Modularity: camera view configured in config.json, loaders, mini geometry library, rasterizer factory

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Reference

This project is my hands-on take on ssloy's Tinyrenderer. The model used to generate examples with the renderer is the model used in the blog with the permission from creator.

While TinyRenderer prioritizes minimal code, mini-renderer uses a more object-oriented design, making it easier to embed in a GUI or extend for other uses.

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Examples

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▶️ Run

Run ./mini-renderer to see help.

Flags

Required:

• --mode : RASTERIZER_MODE
• --path : path to the output bmp
  Optional:
  
• --config : path to the config json

RASTERIZER_MODE options:

• bin - black & white with basic lighting
• bing - black & white with Gouraud shading
• binp - black & white with Phong shading
• tex - color with basic lighting
• texg - color with Gouraud shading

Example

./mini-renderer --mode bing --path out.tga --config ../config.json

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You can adjust the scene in config.json by tweaking eye and light vectors. Other fields are left in for debugging.

{
  "model_path":   "../obj/african_head.obj",
  "texture_path": "../obj/african_head_diffuse.tga",
  "output_width":  800,
  "output_height": 800,
  "output_depth":  255,
  "eye":      [3.0, -3.0, 6.0],
  "center":   [0.0, 0.0,  0.0],
  "vertical": [0.0, 1.0,  0.0],
  "light":    [0.0, 0.0, -1.0]
}

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✅ Running Tests

Run ctest from build/ folder to run all tests.

After the build, test binaries will be in the output/ folder:

./test_vec
./test_matrix
./test_model
./test_graphics

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📝 License

This project is licensed under the BY-NC-SA 4.0 License.