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I've hit this as well. There are a number of deep technical falsehoods believed by the industry that are very widespread. These falsehoods are so ingrained that pushing against these falsehoods even rationally or logically could land you in hot water. The one that affected me personally has to do with Quaternions.

At the company where I work we convert all of our data to quaternions when transmitting over the wire or for data storage. In the gaming and robotics industry there is a misguided assumption that quaternions are always better, and at my company we force this assumption onto all engineers by using typed protobufs. We can never send EUler angles over the wire, we must always send quaternions.

This is actually fundamentally bad. Like it's not even a design question. It is by logic worse to store things as quaternions. Quaternions are only good for certain transformation calculations. They are not as good for data transmission or storage. So I made a proposal to offer alternatives but I was shot down even by the CEO (who took the time to personally make his own viewpoint known on the entire slack thread out of nowhere) because all of these people buy into the misguided notion that quaternions are always better.

The person I was talking to about this was so hell bent on believing that quaternions are better that if I pressed the point further I could start an all out conflict that could get me fired so I had to stop and pretend (aka lie) to agree.

The fact of the matter is, Quaternions are a higher entropy form of storage for rotation and orientation. You lose information when converting something to a quaternion and this is good for calculation but definitively bad when you choose to use quaternions for data storage or transmission. If you transmit or store things as Euler angles you CAN always convert it to a quaternion. The conversion is trivial and mostly a non-issue.

The problem is that once you have a quaternion you can't go back to Euler Angles without additional assumptions. The back conversion algorithm is not One to One. So by forcing this format as storage you are limiting the future productivity of this data by keeping it in a higher entropy form.

Each quaternion is realized by TWO euler angles within a 360 range of motion across 3 axis-es. When you convert something to a quaternion you cannot go backwards. You cannot find the original euler angle where the quaternion came from because you HAVE two options to choose from.

For gaming this problem is not so apparent because you're in a virtual world and having everything exist in quaternions is ok because rotational orientations don't have to be realized by actual movement or rotations. The computer simply draws the object at the required orientation.

But real world rotations HAVE to be realized by euler angles. You cannot Orient something in reality without actually turning it about an axis. Gimbal lock cannot be erased in the real world and even the Apollo module suffered from this phenomenon despite the fact that the engineers knew about quaternions. People at my company seem to think the issue disappears once you switch everything to quaternions.

Thus for something as simple as having one robot gimbal imitate another... if the communication protocol between them both was exclusively quaternions (with no additional assumptions) the imitating robot can choose an alternative euler angle to project it's motion onto and the two robots WILL not be be in sync. Total information Loss.

So all in all this proposal never went through. I was shut down by stubbornness and over confidence by "robotics experts" who've been brainwashed by false dogma. The people I was proposing this to told me that I should trust the extensive experience their backgrounds of building self driving cars at uber and building robots at CMU. Yeah I respect that but can you not see the literal logic of the issue here? I don't respect people who aren't able to see logic.

The company culture is just part of the story, these falsehoods are likely held industry wide and you'd get these issues everywhere. False Dogma is powerful. Try telling a christian that walking on water is ludicrous when looking at it logically. It's same issue here. Peoples' brains will fight logic if it goes against their beliefs.

Very likely I might even get replies to this post who have so much confidence in quaternions that they'll come up with a retort that doesn't fully understand the problem I illustrated here.



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