smallpt4D: simple ray tracer for 4D scenes

• written by S. Kaji
• Based on: smallpt: Global Illumination in 99 lines of C++ by Kevin Beason

Build

Requirements:

• CMake 3.16+
• A C++17 compiler
• Eigen3 headers
• OpenMP runtime
• OpenCL runtime/SDK (optional, for GPU mode via -g)

cmake --build build --config Release

Usage

Edit scene_definition.cpp to define a 4D scene. Then,

./build/smallpt4d

Command-line options:

./build/smallpt4d [-m min_bounce] [-s samples] [-w width] [-h height] [-f frames] [-g]

• -m <int>: minimum bounce count before Russian roulette (default: 5)
• -s <int>: samples per pixel (default: 100)
• -w <int>: output width in pixels (default: 1080)
• -h <int>: output height in pixels (default: 1200)
• -f <int>: number of frames (default: 200)
• -g: enable OpenCL GPU backend when available (sometimes quality degrades due to fp32 precision)

Combine rendered images into a side-by-side video for HMDs:

python3 create_video.py

Play the produced video in a media player such as Whirligig (press Y to enter SBS mode in Whirligig).