Attention: Here be dragons
This is the
(unstable) version of this documentation, which may document features
not available in or compatible with released stable versions of Godot.
A 2D polyline shape used for physics collision.
Being just a collection of interconnected line segments, ConcavePolygonShape2D is the most freely configurable single 2D shape. It can be used to form polygons of any nature, or even shapes that don't enclose an area. However, ConvexPolygonShape2D is hollow even if the interconnected line segments do enclose an area, which often makes it unsuitable for physics or detection.
Note: When used for collision, ConcavePolygonShape2D is intended to work with static CollisionShape2D nodes like StaticBody2D and will likely not behave well for CharacterBody2Ds or RigidBody2Ds in a mode other than Static.
Warning: Physics bodies that are small have a chance to clip through this shape when moving fast. This happens because on one frame, the physics body may be on the "outside" of the shape, and on the next frame it may be "inside" it. ConcavePolygonShape2D is hollow, so it won't detect a collision.
Performance: Due to its complexity, ConcavePolygonShape2D is the slowest 2D collision shape to check collisions against. Its use should generally be limited to level geometry. If the polyline is closed, CollisionPolygon2D's CollisionPolygon2D.BUILD_SOLIDS mode can be used, which decomposes the polygon into convex ones; see ConvexPolygonShape2D's documentation for instructions.
PackedVector2Array segments =
The array of points that make up the ConcavePolygonShape2D's line segments. The array (of length divisible by two) is naturally divided into pairs (one pair for each segment); each pair consists of the starting point of a segment and the endpoint of a segment.