Curve3D

    Category: Core

    Describes a Bezier curve in 3D space.

    Properties

    Description

    This class describes a Bezier curve in 3D space. It is mainly used to give a shape to a , but can be manually sampled for other purposes.

    It keeps a cache of precalculated points along the curve, to speed further calculations up.

    The distance in meters between two adjacent cached points. Changing it forces the cache to be recomputed the next time the or get_baked_length function is called. The smaller the distance, the more points in the cache and the more memory it will consume, so use with care.

    • up_vector_enabled

    If , the curve will bake up vectors used for orientation. This is used when PathFollow.rotation_mode is set to . Changing it forces the cache to be recomputed.

    Method Descriptions

    • void add_point ( Vector3 position, in=Vector3( 0, 0, 0 ), Vector3 out=Vector3( 0, 0, 0 ), at_position=-1 )

    Adds a point to a curve, at position, with control points in and out.

    If at_position is given, the point is inserted before the point number at_position, moving that point (and every point after) after the inserted point. If at_position is not given, or is an illegal value (at_position <0 or at_position >= [method get_point_count]), the point will be appended at the end of the point list.

    Removes all points from the curve.

    • float get_baked_length ( ) const

    Returns the total length of the curve, based on the cached points. Given enough density (see ), it should be approximate enough.

    Returns the cache of points as a .

    Returns the cache of tilts as a .

    Returns the cache of up vectors as a .

    • float get_closest_offset ( to_point ) const

    Returns the closest offset to to_point. This offset is meant to be used in interpolate_baked or .

    to_point must be in this curve’s local space.

    • Vector3 get_closest_point ( to_point ) const

    Returns the closest point (in curve’s local space) to to_point.

    to_point must be in this curve’s local space.

    • int get_point_count ( ) const

    Returns the number of points describing the curve.

    • get_point_in ( int idx ) const

    Returns the position of the control point leading to the vertex idx. If the index is out of bounds, the function sends an error to the console, and returns (0, 0, 0).

    • get_point_out ( int idx ) const

    Returns the position of the control point leading out of the vertex idx. If the index is out of bounds, the function sends an error to the console, and returns (0, 0, 0).

    Returns the position of the vertex . If the index is out of bounds, the function sends an error to the console, and returns (0, 0, 0).

    • get_point_tilt ( int idx ) const

    Returns the tilt angle in radians for the point idx. If the index is out of bounds, the function sends an error to the console, and returns 0.

    • interpolate ( int idx, t ) const

    Returns the position between the vertex idx and the vertex idx + 1, where t controls if the point is the first vertex (t = 0.0), the last vertex (t = 1.0), or in between. Values of t outside the range (0.0 >= t <=1) give strange, but predictable results.

    If idx is out of bounds it is truncated to the first or last vertex, and t is ignored. If the curve has no points, the function sends an error to the console, and returns (0, 0, 0).

    • Vector3 interpolate_baked ( offset, bool cubic=false ) const

    Returns a point within the curve at position offset, where offset is measured as a pixel distance along the curve.

    To do that, it finds the two cached points where the offset lies between, then interpolates the values. This interpolation is cubic if cubic is set to , or linear if set to false.

    • interpolate_baked_up_vector ( float offset, apply_tilt=false ) const

    Returns an up vector within the curve at position offset, where offset is measured as a distance in 3D units along the curve.

    To do that, it finds the two cached up vectors where the offset lies between, then interpolates the values. If apply_tilt is true, an interpolated tilt is applied to the interpolated up vector.

    If the curve has no up vectors, the function sends an error to the console, and returns (0, 1, 0).

    • Vector3 interpolatef ( fofs ) const

    Returns the position at the vertex fofs. It calls interpolate using the integer part of fofs as idx, and its fractional part as t.

    • void remove_point ( idx )

    Deletes the point idx from the curve. Sends an error to the console if idx is out of bounds.

    • void set_point_in ( int idx, position )

    Sets the position of the control point leading to the vertex idx. If the index is out of bounds, the function sends an error to the console.

    • void set_point_out ( int idx, position )

    Sets the position of the control point leading out of the vertex idx. If the index is out of bounds, the function sends an error to the console.

    • void set_point_position ( int idx, position )

    Sets the position for the vertex idx. If the index is out of bounds, the function sends an error to the console.

    Sets the tilt angle in radians for the point idx. If the index is out of bounds, the function sends an error to the console.

    The tilt controls the rotation along the look-at axis an object traveling the path would have. In the case of a curve controlling a PathFollow, this tilt is an offset over the natural tilt the calculates.

    Returns a list of points along the curve, with a curvature controlled point density. That is, the curvier parts will have more points than the straighter parts.

    This approximation makes straight segments between each point, then subdivides those segments until the resulting shape is similar enough.

    controls how many subdivisions a curve segment may face before it is considered approximate enough. Each subdivision splits the segment in half, so the default 5 stages may mean up to 32 subdivisions per curve segment. Increase with care!