Curve3D
继承: Resource
< RefCounted
< Object
Describes a Bézier curve in 3D space.
描述
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.
属性
方法
属性说明
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.
方法说明
void
add_point ( position: Vector3
, in: Vector3
= Vector3(0, 0, 0), out: Vector3
= Vector3(0, 0, 0), index: int
= -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 ( ) const1
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 ( ) const1
Returns the cache of points as a PackedVector3Array
.
PackedFloat32Array
get_baked_tilts ( ) const1
Returns the cache of tilts as a PackedFloat32Array
.
PackedVector3Array
get_baked_up_vectors ( ) const1
Returns the cache of up vectors as a PackedVector3Array
.
If up_vector_enabled
is false
, the cache will be empty.
float
get_closest_offset ( to_point: Vector3
) const1
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 ( to_point: Vector3
) const1
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 ( idx: int
) const1
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 ( idx: int
) const1
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 ( idx: int
) const1
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 ( idx: int
) const1
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 ( idx: int
)
Deletes the point idx
from the curve. Sends an error to the console if idx
is out of bounds.
Vector3
sample ( idx: int
, t: float
) const1
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 ( offset: float
= 0.0, cubic: bool
= false ) const1
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 ( offset: float
, apply_tilt: bool
= false ) const1
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 ( offset: float
= 0.0, cubic: bool
= false, apply_tilt: bool
= false ) const1
Returns a 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. See also sample_baked
.
Vector3
samplef ( fofs: float
) const1
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 ( idx: int
, position: Vector3
)
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 ( idx: int
, position: Vector3
)
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 ( idx: int
, position: Vector3
)
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 ( idx: int
, tilt: float
)
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 ( max_stages: int
= 5, tolerance_degrees: float
= 4 ) const1
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 ( max_stages: int
= 5, tolerance_length: float
= 0.2 ) const1
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.
本方法通常需要用户覆盖才能生效。
本方法无副作用,不会修改该实例的任何成员变量。
本方法除了能接受在此处描述的参数外,还能够继续接受任意数量的参数。
本方法用于构造某个类型。
调用本方法无需实例,可直接使用类名进行调用。
本方法描述的是使用本类型作为左操作数的有效运算符。
这个值是由下列位标志构成位掩码的整数。
无返回值。