Analytic SH Area Light

Implementation of paper: Analytic Spherical Harmonic Coefficients for Polygonal Area Lights

Usage

run demo

run real-time demo with provided datas:

run.bat

run full pipeline (precompute + real-time)

place your data under data/ folder as:

• mesh: data/your_mesh.obj
• envmap: data/your_envmap.exr

and modify the variables in run_full.bat:

set envmap=your_envmap
set mesh=your_mesh

and run:

run_full.bat

TODO

• Use trimesh for mesh io replacing open3d
• Use pytorch-minimize to optimize zonal harmonics

Reference

1. "An efficient representation for irradiance environment maps" by Ravi Ramamoorthi, Pat Hanrahan, SIGGRAPH 2001
2. "Sparse Zonal Harmonic Factorization for Efficient SH Rotation" by Derek Nowrouzezahrai et al., SIGGRAPH 2012
3. "spherical-harmonics" https://github.com/google/spherical-harmonics
4. "SphericalHarmonics" https://github.com/chalmersgit/SphericalHarmonics
5. "Analytic Spherical Harmonic Coefficients for Polygonal Area Lights" by Jingwen Wang, Ravi Ramamoorthi, SIGGRAPH 2018
6. "Applications of Irradiance Tensors to the Simulation of Non-Lambertian Phenomena" by James Arvo, SIGGRAPH 1995