The real "a-ha" demystifying moment for me was not so much learning about the elementary rotation, translation or even perspective projection operations. It was understanding how all of those operations can be composed together into a single transformation and that all that 3D graphics really is, is transforming coordinates from one relative space to another.

One important revelation in that regard for instance, was that moving a camera within a world is mathematically exactly the same as moving the world in the opposite direction relative to the camera. Once you get a feel for how transformations and coordinate spaces work, you can start playing around with them and a whole new world of possibilities opens up to you.

The way he animated points with an increasing z value made it click for me. Now, when I look at the formula it makes sense. The larger the value of z, the smaller your projected x and y will be. This checks out because things get smaller as they move farther away. Something that’s twice as far away will seem half as big.

The rotation formula eludes me.

This formula also leads to weird geometric perceptual distortions like when one stands in front of a tall building, looks up and down and the shape of the building changes depending on the angle of the view. VR got rid of that.

To me the formula mystifies things. It should be made clear that it is a simple application of pythagore's theorem,

(i didn't see the video except the beginning to check what was the "mysterious formula".)

His application `boomer` is the best desktop zoom app for X11! Bound to a keyboard shortcut its very useful for debugging graphics layout errors during development.

I always found it odd that perspective had to be "discovered" by artists, but a little digging online turned up this interesting, detailed look at its history.

https://www.essentialvermeer.com/technique/perspective/histo...

When I was a little kid trying to do 3D graphics on my Spectrum I couldn't find any books with the algorithm for how it worked. I remember my artistic friend and I sitting down with reams of graph paper trying to figure out how to do it. It's so simple and obvious after you learn, but until you do I felt like a caveman.

Jim Blinn's Corner (1996) also has a good chapter/article, "The Homogenous Perspective Transform."