Does every serious game have its own editor like Unity3d?

Question

Game development

Good afternoon, tell me, when they create a new game, do they write their own visual editor from scratch for drawing, adding effects and movements?
For example, to add a new unit to a Warcraft or Starcraft game, is it possible to do this if there are graphic editors for these games or are the games not tied to how the picture or effect was created for it?

Answer 1

For large games, their own tools are inevitably written, because artists need to quickly check how the art looks in the game, game designers need to correct the balance, narrators add commas to dialogues, and so on, and forcing everyone to compile a game from C ++ sorts is prohibited by the international convention on the humane treatment of prisoners and the declaration of human rights. Therefore, there will inevitably be some tools where you can feed png, mp3 or txt, move the sliders and see how it will be in the game.
Sometimes Unity3D or UE comes out of it, sometimes TES Construction Set, sometimes it remains in the depths.
Disclaimer: I have never worked in game development :)