Texture filtering is an important implementation detail of every rendering system. Its purpose is to achieve high-quality rendering of textured surfaces, while avoiding artifacts, such as aliasing, Moire patterns, and unnecessary overblur. In this chapter, we extend the ray cone method for texture level of detail so that it also can handle refraction. Our method is suitable for current game engines and further bridges the gap between offline rendering and real-time ray tracing.
- Compared to our other papers about ray cones (Ray Tracing Gems 1 and Journal of Computer Graphics Tools), we (unfortunately) used half the cone angle in this paper, while the other papers used the entire cone angle as the spread angle. Technically, this is not an error, but it would have been better to use the same definitions. Our code in Falcor uses the entire cone angle.