Illumination References

Figure 5 from Andrew S. Glassner, "An Overview of Ray Tracing" in An Introduction to Ray Tracing, Andrew Glassner, ed., Academic Press Limited, 1989.

Figure 15 from Andrew S. Glassner, "Surface Physics for Ray Tracing" in An Introduction to Ray Tracing, Andrew Glassner, ed., Academic Press Limited, 1989.

Figure 4a from R. L. Cook and K. E. Torrance, "A Reflectance Model for Computer Graphics", Proceedings of SIGGRAPH 81, 1981, pp. 307-316.

Figure 4b from R. L. Cook and K. E. Torrance, "A Reflectance Model for Computer Graphics", Proceedings of SIGGRAPH 81, 1981, pp. 307-316.

Figure 5a from R. L. Cook and K. E. Torrance, "A Reflectance Model for Computer Graphics", Proceedings of SIGGRAPH 81, 1981, pp. 307-316.