December 2022

Description: The null scattering path integral formulation allows us to perform MIS for any type of media (homogeneous or heterogeneous). Previous MIS techniques were unbiased only for homogeneous volumes, but this technique allows us to perform unbiased MIS for heterogeneous volumes as well. We implement a GPU-accelerated version of the algorithm using CUDA and NanoVDB for reading volumetric data. Additionally, we use some volumetric models from EmberGen.

See our Github for full technical and implementation details.

Teammates: Nick Moon

Paper:

• A null-scattering path integral formulation of light transport, Miller et al., SIGGRAPH 2019

Features:

• Heterogeneous media rendering
  • Null-scattering MIS (next-event estimation and phase function sampling)
  • Delta tracking
• Homogeneous media rendering
• Interactions between surface and media
• Volumes on the inside and outside of objects (medium interfaces)
• Loading .vdb files with NanoVDB
• Basic image-based lighting
• LBVH for mesh intersection optimization
• Interactive GUI with ImGUI