A volumetric cloud render based on OpenGL. Implementing:
- Preetham model to render the sun and sky
- Pre-computed Perlin-worley noise to calculate cloud density
- Simplex 3D noise to calculate curl
- Ray marching to calculate cloud lighting
Compile and build using CMake. Configure using IDE or build with command line
cmake --build build --config Release --target all -j 12
- C++ 20
- OpenGL 3
- GLFW, GLEW, GLM(included in external)
| Key | Operation |
|---|---|
| Drag mouse | Tilt camera |
| W | Forward |
| A | Backward |
| S | Left |
| D | Right |
| Q | Up |
| Z | Down |
| ↑ | Rise sun |
| ↑ | Fall sun |
| ← | Decrease coverage (less rain cloud) |
| → | Increase coverage (more rain cloud) |
Frame rate is outputed to stdout per 5s.
Please don't go above the clouds, below the surface, or outside of radius as it triggers bugs!
- Sample Perlin-Worley noise to create cloud models. (See perlinworley.h)
- Calculate light intensity going through clounds based on Beer-Lambert law. (Line 271 in sky.frag)
- Account for scattering. (Line 265 in sky.frag)
- Account for absorption. (Line 279 in sky.frag)
- Calculate sky color in four discrete times of a day: sunrise, noon, sunset and night, using Preetham model. (Line 55 in sky.frag)
- Use ray marching to render clouds. (Line 242 in sky.frag)
- FPS ≥ 3. (See
stdout) - Use a user-interface to determine rain cloud density. (See above)
The Real Time Volumetric Cloudscapes of Horizon Zero Dawn
NUBIS: AUTHORING REAL-TIME VOLUMETRIC CLOUDSCAPES WITH THE DECIMA ENGINE
A Practical Analytic Model for Daylight