Volume Renderer

A real-time GPU volume renderer in C++17 / OpenGL 4.3 / GLSL. It ray-casts a scalar volume (synthetic first, real electron-microscopy data later) in a single fragment-shader pass through a 3D texture, with a transfer function, gradient-based lighting, an orbit camera, and an interactive parameter UI.

Status: in development. The renderer ray-casts a synthetic volume in a single fragment-shader pass — orbit camera, slab-based box traversal, front-to-back compositing, and a colour/opacity transfer function with step-size-independent opacity are all working. Still to come: gradient-based lighting, an interactive parameter UI, and loading a real electron-microscopy dataset. Screenshots and dataset provenance will be added as those features land.

Milestones

The project is built in ordered milestones; each maps to a commit tagged [M#].

• M0 — Build system, dependencies, and a cleared OpenGL window
• M1 — Shader pipeline and fullscreen-quad rendering
• M2 — Orbit camera and per-pixel ray generation
• M3 — Synthetic volume generation and 3D-texture upload
• M4 — Single-pass ray-casting (emission–absorption)
• M5 — Transfer function with opacity correction
• M6 — Gradient-based Blinn-Phong lighting
• M7 — Interactive parameter UI
• M8 — Load and render a real cryo-EM volume
• M9 — Marching-cubes isosurface extraction (stretch)

Requirements

• A C++17 compiler (MSVC 2022 on Windows; GCC/Clang on Linux)
• CMake ≥ 3.21
• Conan 2.x (pip install "conan>=2.0,<3")
• A GPU/driver supporting OpenGL 4.3 core profile

Build

# 1. One-time: create a Conan profile for your toolchain
conan profile detect --force

# 2. Resolve and build dependencies (C++17 to match the project standard)
conan install . --output-folder=build --build=missing -s compiler.cppstd=17

# 3. Configure and build
cmake --preset conan-default
cmake --build build --config Release

# 4. Run the tests
ctest --test-dir build -C Release --output-on-failure

The executable is produced under build/ (e.g. build/Release/volume_renderer on Windows). Press Esc or close the window to exit.

Dependencies

All third-party libraries are resolved through Conan (conanfile.txt):

Library	Purpose
GLFW	Windowing and input
glad	OpenGL 4.3 core function loader
GLM	Vector/matrix math
Dear ImGui	Interactive parameter UI
GoogleTest	Unit tests (via CTest)

License

MIT — see LICENSE.