Drew Fitzpatrick DrewFitz

CUSTOM GAME ENGINES: A Small Study

WARNING: Article moved to separate repo to allow users contributions: https://github.com/raysan5/custom_game_engines

A couple of weeks ago I played (and finished) A Plague Tale, a game by Asobo Studio. I was really captivated by the game, not only by the beautiful graphics but also by the story and the locations in the game. I decided to investigate a bit about the game tech and I was surprised to see it was developed with a custom engine by a relatively small studio. I know there are some companies using custom engines but it's very difficult to find a detailed market study with that kind of information curated and updated. So this article.

Nowadays lots of companies choose engines like [Unreal](https:

	//
	// Lookup Tables for Transvoxel's Modified Marching Cubes
	//
	// Unlike the original paper (Marching Cubes: A High Resolution 3D Surface Construction Algorithm), these tables guarantee
	// a closed mesh "whose connected components are continuous and free of holes."
	//
	// Rotations are prioritised over inversions so that 3 of the 6 cases containing ambiguous faces are never added. 3 extra
	// cases are added as a post-process, overriding inverses through custom-build rotations to eliminate the rest.
	//
	// Uses the exact same co-ordinate system as https://gist.github.com/dwilliamson/c041e3454a713e58baf6e4f8e5fffecd

	//
	// Lookup Tables for Marching Cubes
	//
	// These tables differ from the original paper (Marching Cubes: A High Resolution 3D Surface Construction Algorithm)
	//
	// The co-ordinate system has the more convenient properties:
	//
	// i = cube index [0, 7]
	// x = (i & 1) >> 0
	// y = (i & 2) >> 1