Is there a need to code a new 3D engine?

Question

Coding a new 3D engine is fascinating but I there are so many out there. Is it sane for a programmer to start a new one? Are there industry sections in need?

Answer 1

Generally, you code one if you have a need for one and there doesn't already exist one that suits your need.

Is there someone out there who needs an engine built for them because there doesn't exist one that suits their needs? Probably.

Answer 2

Reasons to do it:

1. You want to learn about how to make a 3D engine, and don't really care if anyone but yourself uses it.
2. None of the existing engines do what you want and it's too much trouble to modify their source code (if you can even get it).
3. You have such an awesome idea and no other engine has done it so you need to do it because whatever you're doing doesn't exist yet.

Reasons not to do it:

1. You don't have enough of these resources: time/budget/expertise.
2. An existing engine fits your needs perfectly.

Answer 3

This is highly similar to the question should I write my own program/technology/framework X instead of using an existing one?" and that has been asked plenty, so I won't go over the usual boilerplate reasons.

While the answer to this question will always be somewhat subjective, a great deal depends on the context in which it is asked.

If it's being asked along the lines of I want to learn about game engines and rendering then it always can be beneficial to write your own game engine as developing the code is arguably the best way to learn. However, there may already exist good open sourced well documented engines to learn from as well.

If it's a commercial endeavor, then it's more of an issue of whether or not an existing engine provides what is needed. Modern commercial engines are written by some truly brilliant people and contain all the latest bells and whistles so it's more than likely they would suffice. This is evident by the sheer number of games that have been developed on two of the most popular game engines: idTech and Unreal engine. However, there still may be no tech related prohibiting factors to using an existing engine where writing your own is better. Such as if it can afford to be done, whether the engine can be licensed adequately, and, if the license can be afforded.