Comment by yakcyll

It's worth remembering when deciding on rolling out your own engine that this is a multi-layer trade-off as well, I have an anecdote on this.

I have decided a couple years back that my setup will have a hand-rolled physics engine, specifically for the reasons you outlined - having complete understanding over what the code does, how it's structured and how it manages data - but after starting actually-not-so-arduous process of getting it together, it quickly became rather clear that whatever I could implement would pale in comparison to solutions that are robust, field-tested and generally created by professionals.

Physics development in particular is known for wonky nonsense, but there are better and worse heuristics and ways to deal with their shortcomings; a handful of books and Youtube presentations still couldn't prepare me for the actual depth of the problems ahead. What I have now works, is relatively stable in initial demos and I am proud of it, I'm going to tweak and use it in the game I'm working on. It is however pretty obvious already that a lot of time is yet to be spent on massaging jank out of the equations.

I wholeheartedly recommend spending more than several weeks on implementing various subsystems if one either is generally interested in how these things work or silently wishes for that badge of honour (it shines brightly). However, as they say, if you want to make games, do NOT make an engine. Not just because of the time it takes - it doesn't have to take that much (even though it usually does) - but also because along with total control over the medium for expressing your creative vision, it gives you total responsibility for it as well. Sometimes it's better to work in the confines of rules set out by actual engine developers.