how shaders work- using Excel =LET(x,(COLUMN()-24)/15,y,(ROW()-15)/15,SIN(SQRT(x*x+y*y)*10-t)) Each cell (pixel) computes its colour just from its coordinates- so the GPU can massively parallelise them. The trick is writing the formula to draw the picture you want

I snuck a t in there. It’s a named cell wired to that slider that every cell reads. In a shader that would be a ‘uniform’. Nudge it and all 1363 cells recompute from scratch. Still stateless cell to cell and frame to frame- every value is just f(x, y, t)

Here it is as a real shader

(This is a fragment shader- runs once per pixel and returns a colour)

I know some teams that run full 2D CFD simulations in Excel for prototyping. No joke 😅 Makes me wanna cry though.

Reminds me a little of

Now have it update based on time!

Can you generate the formula for whatever shader “picture” you want using the same Fourier transform trick people use to get waves to draw any image (but across 3D ofc; if you want it to animate like yours)

There's this whole category of people where if you put something in Excel where it shouldn't be, it all of the sudden makes sense

what a clever way to teach the concept

I love it, thank you Matt!

I heard someone wrote finite difference time domain simulations in excel.

You can also transform vertices and rasterize triangles in excel

We need to see an excel ray tracer or rasterizer

Can you do a raytracer this way?

this is such a clever way to explain shader lol now do bump map

This is the coolest Excel thing I see.

Perfect, now get Conway’s Game of Life going in Excel

Abomination! But cool.

No shade

You could pass pixel data as uniform via another sheet.

Cool

do you ever use this for non-visual things like audio or physics

Cool, but don't you have work to do?!

Expected to see array formula {}

This is very cool!!

Beautiful! Now, do 'Bad Apple'!