Block 4 in earnest: dot product, Fresnel, GGX, the Smith G term. The math behind every PBR shader, written out properly.
I took a week off since I was traveling and used the break to step away from the daily writing rhythm.
What clicked
It was a good refresher to go deeper into the math. I'd explained the dot product and GGX before at a surface level, but writing them out properly with the actual derivations and shader code, clarified where my understanding had gaps.
I also tried to incorporate more visuals this week to demonstrate the math behind some posts more concretely. The Fresnel post benefitted from it; showing F0 behavior at grazing angles is easier with a diagram than a paragraph.
What flopped
I'm starting to question whether ArtStation is the right platform for more technical posts. The traction is lower than earlier in the series, which could be a few things: the audience skews toward portfolio work rather than technical reading, or the audience for this depth of content is just smaller in general, or both. I do not know the answer to that though.
Into next week
The BRDF posts so far covered individual terms in isolation. Next week looks at how they integrate in an actual shader: writing a BRDF from scratch and visualizing the result. Also starting to wrap things up toward the end of the challenge, which I'm ready for.
© 2026 Stefan Groenewoud. All views are my own, not those of my employer.