Path tracer with CPU, OptiX, and Metal backends.

Features

• CPU backend (all platforms)
  • Custom BVH implementation: binned SAH, sweep SAH, median split, and PLOC bottom-up builders
  • BVH widening via greedy collapse
  • Two-level acceleration structure (BLAS/TLAS) with per-instance transforms
  • Lambert diffuse BRDF with direct lighting and shadow rays
  • HDR environment map sampling with Reinhard tonemapping
  • Diffuse and emissive texture support with bilinear sampling
  • BVH debug visualization: traversal step heatmap, primitive test heatmap, first-hit distance
  • BVH statistics (SAH cost, surface area, volume, depth, leaf prim distribution)
• OptiX backend (Windows/Linux, NVIDIA GPUs) with OptiX Denoiser
• Metal backend (macOS) with Metal ray tracing
• Unified GGX microfacet BSDF implementation across GPU backends
• Supported scene formats: OBJ, GLTF

Screenshots

Building

Prerequisites

Windows/Linux (OptiX backend, NVIDIA GPUs only)

• NVIDIA GPU with RT cores (recommended) or Maxwell architecture or newer
• CUDA Toolkit
• OptiX SDK 8.0 or newer
• CMake 3.20 or newer

macOS (Metal backend)

• macOS 13.3 or newer
• Xcode Command Line Tools
• CMake 3.20 or newer

Build Instructions

git clone https://github.com/mateeeeeee/Amber
cd Amber
cmake -B build
cmake --build build

OptiX SDK Path (Windows/Linux only)

If OptiX is not installed in a standard location, specify it manually:

cmake -B build -DOptiX_INSTALL_DIR=/path/to/optix