Because the "secret sauce" isn't a tool to make animations. The secret sauce is being able to explain complex concepts in simple terms, while encouraging curiosity and maintaining math as an approachable topic, for those who may be otherwise intimidated - and additionally coming up with ideas for animations that will help explain those concepts. All the while, maintaining a high level of quality and regularly releasing content, such that you become a "brand".

It's a lot harder to replicate that secret sauce, than it is to replicate some animation engine.

Mathematicians are all experts at symbol manipulation and tend to communicate that way. 3b1b uses geometric analogues that are far more useful than definitions and symbols for learners.

Math teachers are usually stuck using symbols to communicate because not many mathematicians have 3b1b's skill at animating and so can't use the high-bandwidth visual medium like he does. A blackboard can't compete with a 3b1b video; and it isn't just because he thinks clearly, it is because an animation can get more bits of information through in a short period of time and works better with a students short term memory. His custom animation tool is more important than it seems - he can explain more clearly because of a slight-of-hand where he has a much wider communication channel to get his message across.

That being said, the barrier to entry is still high. I suspect any topic he hasn't already covered is going to need specialist knowledge to extend this program.

I like 3b1b's animations, but lets not get ahead of ourselves here.

Mathematicians have been using blackboards and symbols for thousands of years, and its never been a hindrance. While its not as good as video, its more than adequate to explain things and if you still have issues, you can use the many mathematical modeling tools that have existed for years.

Also, many of his topics require in-depth knowledge in the first place and gloss over significant portions of detail because the problems are often specialized. These details are obscured through the many drawings and it gives the viewer a false sense of understanding without actually being able to do the math.

So you're left with a largely conceptual understanding without any syntheses understanding, because, at the end of the day, you have to produce a line by line derivation in order to be considered having understanding.

To expand:

Of all of the math teachers I've had, only one tried to explain things in an understandable way the 3b1b does.

Most math teachers just follow a curriculum and hope repetition drills facts into the students head. 3b1b makes the relationships between systems clear.

In addition, theres proabably not a wide audience for math videos, and this is a good advertisement for his channel. Likely would have been useful when I was in undergrad, but most math terms are gibberish after not using them at all for work.

>why he open sourced this after so long

Did he only do it recently? It was on GitHub already when I watched his video first time.

Yes, it has been on GitHub for some time already

It’s been on github for years.

> after so long of saying it was made for his personal use and wasn’t designed for widespread use.

I'm not sure why you don't trust his explanation? Polishing up personal/internal projects and making them releasable as open source can take a lot of time and effort.

I never said I didn’t trust his explanation. As I recall it seemed like he had no intention of ever making it widely available so was just surprised to see it show up all of the sudden. This is sort of funny, I’m actually a big fan of his work and yet everyone seems to think my question is a knock on him.

The 3b-hive stung you.

Because animations aren't his secret sauce?

Clearly, he is simply a great human.

Because the renderer alone won't help you.