PathFollow2D

Inherits: Node2D < CanvasItem < Node < Object

Point sampler for a Path2D.

Description

This node takes its parent Path2D, and returns the coordinates of a point within it, given a distance from the first vertex.

It is useful for making other nodes follow a path, without coding the movement pattern. For that, the nodes must be children of this node. The descendant nodes will then move accordingly when setting the progress in this node.

Properties

bool

cubic_interp

true

float

h_offset

0.0

float

lookahead

4.0

bool

loop

true

float

progress

0.0

float

progress_ratio

0.0

bool

rotates

true

float

v_offset

0.0


Property Descriptions

bool cubic_interp = true

  • void set_cubic_interpolation ( bool value )

  • bool get_cubic_interpolation ( )

If true, the position between two cached points is interpolated cubically, and linearly otherwise.

The points along the Curve2D of the Path2D are precomputed before use, for faster calculations. The point at the requested offset is then calculated interpolating between two adjacent cached points. This may present a problem if the curve makes sharp turns, as the cached points may not follow the curve closely enough.

There are two answers to this problem: either increase the number of cached points and increase memory consumption, or make a cubic interpolation between two points at the cost of (slightly) slower calculations.


float h_offset = 0.0

  • void set_h_offset ( float value )

  • float get_h_offset ( )

The node's offset along the curve.


float lookahead = 4.0

  • void set_lookahead ( float value )

  • float get_lookahead ( )

How far to look ahead of the curve to calculate the tangent if the node is rotating. E.g. shorter lookaheads will lead to faster rotations.


bool loop = true

  • void set_loop ( bool value )

  • bool has_loop ( )

If true, any offset outside the path's length will wrap around, instead of stopping at the ends. Use it for cyclic paths.


float progress = 0.0

  • void set_progress ( float value )

  • float get_progress ( )

The distance along the path, in pixels. Changing this value sets this node's position to a point within the path.


float progress_ratio = 0.0

  • void set_progress_ratio ( float value )

  • float get_progress_ratio ( )

The distance along the path as a number in the range 0.0 (for the first vertex) to 1.0 (for the last). This is just another way of expressing the progress within the path, as the offset supplied is multiplied internally by the path's length.


bool rotates = true

  • void set_rotates ( bool value )

  • bool is_rotating ( )

If true, this node rotates to follow the path, with the +X direction facing forward on the path.


float v_offset = 0.0

  • void set_v_offset ( float value )

  • float get_v_offset ( )

The node's offset perpendicular to the curve.