Nikita LisitsaApr 25, 2024

New blog post: Demystifying multiple importance sampling

It is a simple thing that turns out to be confusing to a lot of us rendering engineers. I try to explain it in detail here with path-tracing examples!

https://lisyarus.github.io/blog/posts/multiple-importance-sampling.html

Demystifying multiple importance sampling

lisyarus blog
Show threadj_bertolottiApr 25, 2024
@lisyarus I am biased by years of working in optics, but using ω as a direction feels cursed.
Show threadLesley Lai
@j_bertolotti @lisyarus It is very common in graphics literature though. It is indeed cursed as some people using it as directions while other people use it for angles
Apr 26, 2024 at 9:14amWeb
Show threadj_bertolottiApr 26, 2024
@lesley Beside, if one uses it as a direction, there should be some visual indication you are talking about a unit vector, e.g. rĖ‚.
@lisyarus
Show threadNikita LisitsaApr 26, 2024

@j_bertolotti @lesley Tbh I don't like this practice - it clutters formulas way too much. From my experience, this is rarely done in in math literature.

You still have to remember which variable means what, so remembering what is a vector and what isn't doesn't seem like it changes that much.

Show threadj_bertolottiApr 26, 2024
@lisyarus Hard disagree. Together with using standard symbols for standard quantities (in Physics&co the same quantities keep turning up over and over), it helps parsing an otherwise complex equation at a glance.
@lesley
Show threadNikita LisitsaApr 26, 2024
@j_bertolotti Well, as @lesley said above, the notation is actually standard in graphics literature.
Show threadLesley LaiApr 26, 2024
@lisyarus @j_bertolotti I always find working memory overload to be one of the major obstacles when reading math-heavy literature, so I definitely appreciate whatever notations that alleviate this cognitive burden
Show threadj_bertolottiApr 26, 2024
@lisyarus Well, as I said in my first comment, I am biased 🙂 @lesley