Taming the shadow Terminator

ABSTRACT

A longstanding problem with the use of shading normals is the discontinuity introduced into the cosine falloff where part of the hemisphere around the shading normal falls below the geometric surface. Our solution is to add a geometrically derived shadowing function that adds minimal additional shadowing while falling smoothly to zero at the terminator. Our shadowing function is simple, robust, efficient and production proven.

References

1. Alejandro Conty Estevez, Pascal Lecocq, and Clifford Stein. 2019. A Microfacet-Based Shadowing Function to Solve the Bump Terminator Problem. Ray Tracing Gems (2019), 127.
2. Vincent Schüssler, Eric Heitz, Johannes Hanika, and Carsten Dachsbacher. 2017. Microfacet-based normal mapping for robust Monte Carlo path tracing. ACM Transactions on Graphics (TOG) 36, 6 (2017), 205.

Index Terms

• Computing methodologies

  • Computer graphics

    • Rendering

      • Ray tracing