A side project which aims to build an efficient photorealistic software renderer.

• Written in C++14
• Developed for Windows and Linux
• Optimized using SSE and AVX intrinsics (especially in performance-critical and low level math code)
• Parsing scene description from a JSON file

• Low discrepancy sampling (scrambled Halton sequence)
• Adaptive sampling (using more samples in noisy image areas)
• Spectral rendering using hero wavelength method (Note: disabled with a macro by default)
• Debug rendering mode (for visualizing depth, normal vectors, material parameters, etc.)
• Camera simulation:
  • Depth of Field (circle or polygonal bokeh)
  • Barrel distortion
  • Motion blur

• Bounding Volume Hierarchy (BVH) used for scene and mesh traversal (two levels of BVH)
• Scene object types: Triangle meshes, Sphere, Box, Plane
• Full per-object motion blur (translational and rotational)
• Both single-ray and AVX-optimized stream packet traversal

• Supported light transport algorithms:
  • Naive Path Tracing (sampling only BSDF)
  • Path Tracing with multiple importance sampling (sampling both lights and material BSDF)
  • Bidirectional Path Tracing (with MIS)
  • Vertex Connection and Merging (Note: work in progress, not all lights and BSDFs are working properly)
  • Light Tracing (for debugging)
• Supported light types: point, area (triangle or quad), spherical, directional, background

• Physically based BSDFs: diffuse, metal, dielectric, plastic
• Cook-Torrance BSDF for specular reflection with GGX normal distribution
• Transparency and refraction
• Normal mapping support

• 2D bitmap textures
• Supported pixel formats: 8-bit unsigned int, 32-bit float, 16-bit float, block-compressed BC1, BC4 and BC5
• Supported file formats: BMP, DDS, EXR (thanks to https://github.com/syoyo/tinyexr library)

• Better material model and multilayer materials (e.g. introduce Disney-like "principled" material)
• Procedural textures
• Volumetric rendering
• Optimize traversal and shading with SSE/AVX