The Rendering Equation

L_o(\bf{x},\bf{\omega'})=L_e(\bf{x},\bf{\omega'})+\int_\Omega f_r(\bf{x},\bf{\omega'},\bf{\omega})L_i(\bf{x},\bf{\omega})(\bf{\omega}\cdot\bf{n})d\bf{\omega}

This is the rendering equation of computer graphics, which is a very basic principle to define the interaction of the ray hitting the surface of an object. This was made in public in 1986, almost 20 years ago.
Path tracing softwares, including my software "ktkray", should follow this equation or result in wrong images. It's very clear whether I understand the equation correctly or not. I mean what I see is just what I get. This is the interesting point to create path tracers, and why I have been trying to do this now.

今日まで載せてきた絵は、この式を何億回も計算して出来た絵なんです。
この式の論文発表から２０年たちコンピュータも数万倍早くなったはずですが、
今でも1枚の絵を作るのに数分から数時間かかってしまいます。
他にもっと速い方法はあるんですが、理論的に正しい絵が出来るか？というと、
そうじゃないんですよね〜。
何事も基本が大事、いい絵が出来るまでがんばります。