Curve3D¶
Inherits: Resource < RefCounted < Object
Describes a Bézier curve in 3D space.
Description¶
This class describes a Bézier curve in 3D space. It is mainly used to give a shape to a Path3D, but can be manually sampled for other purposes.
It keeps a cache of precalculated points along the curve, to speed up further calculations.
Properties¶
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Methods¶
void |
add_point ( Vector3 position, Vector3 in=Vector3(0, 0, 0), Vector3 out=Vector3(0, 0, 0), int index=-1 ) |
void |
clear_points ( ) |
get_baked_length ( ) const |
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get_baked_points ( ) const |
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get_baked_tilts ( ) const |
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get_baked_up_vectors ( ) const |
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get_closest_offset ( Vector3 to_point ) const |
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get_closest_point ( Vector3 to_point ) const |
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get_point_in ( int idx ) const |
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get_point_out ( int idx ) const |
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get_point_position ( int idx ) const |
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get_point_tilt ( int idx ) const |
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void |
remove_point ( int idx ) |
sample_baked ( float offset=0.0, bool cubic=false ) const |
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sample_baked_up_vector ( float offset, bool apply_tilt=false ) const |
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sample_baked_with_rotation ( float offset=0.0, bool cubic=false, bool apply_tilt=false ) const |
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void |
set_point_in ( int idx, Vector3 position ) |
void |
set_point_out ( int idx, Vector3 position ) |
void |
set_point_position ( int idx, Vector3 position ) |
void |
set_point_tilt ( int idx, float tilt ) |
tessellate ( int max_stages=5, float tolerance_degrees=4 ) const |
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tessellate_even_length ( int max_stages=5, float tolerance_length=0.2 ) const |
Property Descriptions¶
float bake_interval = 0.2
The distance in meters between two adjacent cached points. Changing it forces the cache to be recomputed the next time the get_baked_points 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.
int point_count = 0
The number of points describing the curve.
bool up_vector_enabled = true
If true, the curve will bake up vectors used for orientation. This is used when PathFollow3D.rotation_mode is set to PathFollow3D.ROTATION_ORIENTED. Changing it forces the cache to be recomputed.
Method Descriptions¶
void add_point ( Vector3 position, Vector3 in=Vector3(0, 0, 0), Vector3 out=Vector3(0, 0, 0), int index=-1 )
Adds a point with the specified position relative to the curve's own position, with control points in and out. Appends the new point at the end of the point list.
If index is given, the new point is inserted before the existing point identified by index index. Every existing point starting from index is shifted further down the list of points. The index must be greater than or equal to 0 and must not exceed the number of existing points in the line. See point_count.
void clear_points ( )
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 bake_interval), it should be approximate enough.
PackedVector3Array get_baked_points ( ) const
Returns the cache of points as a PackedVector3Array.
PackedFloat32Array get_baked_tilts ( ) const
Returns the cache of tilts as a PackedFloat32Array.
PackedVector3Array get_baked_up_vectors ( ) const
Returns the cache of up vectors as a PackedVector3Array.
If up_vector_enabled is false, the cache will be empty.
float get_closest_offset ( Vector3 to_point ) const
Returns the closest offset to to_point. This offset is meant to be used in sample_baked or sample_baked_up_vector.
to_point must be in this curve's local space.
Vector3 get_closest_point ( Vector3 to_point ) const
Returns the closest point on baked segments (in curve's local space) to to_point.
to_point must be in this curve's local space.
Vector3 get_point_in ( int idx ) const
Returns the position of the control point leading to the vertex idx. The returned position is relative to the vertex idx. If the index is out of bounds, the function sends an error to the console, and returns (0, 0, 0).
Vector3 get_point_out ( int idx ) const
Returns the position of the control point leading out of the vertex idx. The returned position is relative to the vertex idx. If the index is out of bounds, the function sends an error to the console, and returns (0, 0, 0).
Vector3 get_point_position ( int idx ) const
Returns the position of the vertex idx. If the index is out of bounds, the function sends an error to the console, and returns (0, 0, 0).
float 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.
void remove_point ( int idx )
Deletes the point idx from the curve. Sends an error to the console if idx is out of bounds.
Vector3 sample ( int idx, float 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 sample_baked ( float offset=0.0, bool cubic=false ) const
Returns a point 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 points where the offset lies between, then interpolates the values. This interpolation is cubic if cubic is set to true, or linear if set to false.
Cubic interpolation tends to follow the curves better, but linear is faster (and often, precise enough).
Vector3 sample_baked_up_vector ( float offset, bool 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).
Transform3D sample_baked_with_rotation ( float offset=0.0, bool cubic=false, bool apply_tilt=false ) const
Similar with interpolate_baked(). The return value is Transform3D, with origin as point position, basis.x as sideway vector, basis.y as up vector, basis.z as forward vector. When the curve length is 0, there is no reasonable way to calculate the rotation, all vectors aligned with global space axes.
Vector3 samplef ( float fofs ) const
Returns the position at the vertex fofs. It calls sample using the integer part of fofs as idx, and its fractional part as t.
void set_point_in ( int idx, Vector3 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. The position is relative to the vertex.
void set_point_out ( int idx, Vector3 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. The position is relative to the vertex.
void set_point_position ( int idx, Vector3 position )
Sets the position for the vertex idx. If the index is out of bounds, the function sends an error to the console.
void set_point_tilt ( int idx, float tilt )
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 PathFollow3D, this tilt is an offset over the natural tilt the PathFollow3D calculates.
PackedVector3Array tessellate ( int max_stages=5, float tolerance_degrees=4 ) const
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.
max_stages 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!
tolerance_degrees controls how many degrees the midpoint of a segment may deviate from the real curve, before the segment has to be subdivided.
PackedVector3Array tessellate_even_length ( int max_stages=5, float tolerance_length=0.2 ) const
Returns a list of points along the curve, with almost uniform density. max_stages 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!
tolerance_length controls the maximal distance between two neighboring points, before the segment has to be subdivided.