volumetric-clouds

A real-time GPU volumetric clouds renderer via OpenGL, based on the SIGGRAPH 2015 talk The Real-time Volumetric Cloudscapes of Horizon: Zero Dawn by Andrew Schneider.

How can I run this?

Only tested on Linux.

Prerequisites

• Qt 6: In order to build and run this program, you will need to have Qt 6 installed on your machine. See https://www.qt.io/product/qt6 for more information.
• OpenGL with GLSL 4.3 or higher: Required for GPU rendering and compute shaders/SSBO.

Build & Run

We have included a CMakeList.txt file for building the program. If you already have Qt installed, you can build and run the program by following these steps:

• Launch Qt Creator and click "Open Project"
• Select and open CMakeLists.txt from the root directory of the project
• Go to Projects - Run Settings - Run, and change "Working directory" to the root directory of the project
• Click the "Run" button to build and start the program

Key Features

• Organic clouds shape generation with 3D fractal Worley noise
• Dynamic clouds movement over time by offsetting noise textures
• Physically-based volume rendering with anistropic scattering to account for directional dependence of light scattering within the clouds
• Rendering compatability with solid objects by compositing with depth and color buffers
• Rich customization options to craft your own clouds: control density, coverage, shape, and lighting of the clouds in the GUI
• Realistic sky that varies throughout a day by modeling atmospheric scattering

Optimizations

• Optimized raymarching with adaptive step sizes and backtracking
• GL Compute Shader to efficiently generate 3D Worley noise textures