I need to write a photo-realistic renderer. I have been looking at ScratchAPixel site, asking a couple of questions here on CG, and going through the Advanced Global Illumination 2nd ed book. I've read about radiometry, probability, Monte Carlo, and a bit on Russian roulette. I'm aware of the rendering equation in its hemispherical and area formulations. I've written a SAH based kd-tree, so am ok for efficient ray casting.
I'm poised to start writing some code alongside reading chapter 5 of my book which is about path tracing algorithms. However, the last half of chapter 4 is taken up with talking about the following concepts:
- The Importance Function
- The Measurement Equation
- Adjoint equations and linear transport operators
- GRDF (Global Reflectance Distribution Function)
These concepts I've not seen appearing elsewhere in my research (if you can call reading a few web pages about GI rendering proper research?). My question is, do I really need to know this stuff to progress to writing my path tracer? I suspect the answer might depend on which type of path tracer I'm going to developer. To start, based upon what little I know, I think it'll be unidirectional.