Debug line drawing

[HuvaaKoodia]

Easily drawing world space debug lines, which are only visible in debug/editor builds, is very useful.

Unity has Debug,DrawLine and Debug,DrawRay for this purpose. Will Godot have something similar?

[aaronfranke]

Related: #16863 (comment)

It might be useful to create a general-purpose "Gizmo" node for usage in the editor or debugging, which could have subnodes for types of gizmos. Lines could certainly be one of those types.

[eon-s]

Since the different nodes have many needs for drawing and the engine already offer methods to draw 2D and 3D, this could be done by a custom node, and be on the asset library (utilities for autoload, children like collision shapes).

[wyrmling]

Sorry, but is it not enough to have primitives draw_* and Line2D?
Or you want to leave them in code and switch off from project settings while building?
Will it have drawback on performance, as GDScript is not a C#?

[kaadmy]

This issue doesn't specify 2D or 3D, since 2D already supports immediate line drawing.

[Calinou]

Closing in favor of godotengine/godot-proposals#112, as feature proposals are now tracked on the Godot proposals repository.