MatrixCurve

class MatrixCurve

A Matrix curve value.

This object is a special curve built from control matrices, and that outputs a matrix. The position output of the curve is defined by piecewise cubic Splines between the control matrices and along their “main” axis. So are the matrix output’s scale and shear, while its rotation is defined using cubic interpolation of the rotations of the control matrices. The tangents of the positional cubic Splines are automatically computed from the control matrices’ rotation around the “main” axis.:cvar MatrixCurve default_value: Static. The default value.

Methods

__init__	Constructor(s)
closest(p, r, error, max_try)	Compute the curve closest matrix to p.
evaluate(u)	Evaluate the curve at a u coordinate, oriented along the tangent.
length(start, end, error)	Compute the curve length between the start and end u parameters.
main_axis()	rtype MainAxis
mode()	rtype OrientationMode
param_from_length(length, error, max_try)	Compute the parameter for the given arc length.
read_matrices()	Return the readable curve matrices.
tessellate(start, end, samples, uniform)	Builds the line mesh for the sub-part of the curve delimited by start and end.
type()	rtype CurveType
write_matrices()	Return the writable curve matrices.

Properties

default_value

class CurveType

Members:

ConstrainedBezier : The curve is a piecewise cubic Bezier curve, whose internal tangents are driven by the control matrices.

Bezier : The curve is a piecewise cubic Bezier curve, whose internal tangents are automatic.

Spline : The curve is a Nurbs curve defined from the control positions.

__init__()

class MainAxis

Members:

X : Use the X axis.

Y : Use the Y axis.

Z : Use the Z axis.

MX : Use the negated X axis.

MY : Use the negated Y axis.

MZ : Use the negated Z axis.

__init__()

class OrientationMode

Members:

Free : The orientation along the curve is given by the cubic interpolation of the control matrices.

Constrained : The orientation along the curve is computed so that the main axis is tangent to the curve.

__init__()

__init__()

Constructor(s)

Shape (v: Value)

Cast a Value object in Shape.

If v has not the good type, a default value is constructed.

closest(p: Imath.V3d, r: Imath.M44d, error: double, max_try: int) → double

Compute the curve closest matrix to p.

Returns the curve parameter value of the closest point.

Parameters

• p (Imath.V3d) – The position to project on the curve

• r (Imath.M44d) – If not null, it is filled with the closest curve matrix

• error (double) – The minimum error in vertex space

• max_try (int) – Maximum numbr of try

Return type

double

evaluate(u: double) → Imath.M44d

Evaluate the curve at a u coordinate, oriented along the tangent.

Return type

Imath.M44d

length(start: double, end: double, error: double) → double

Compute the curve length between the start and end u parameters.

Parameters

• start (double) – The starting u parameter of the arc

• end (double) – The ending u parameter of the arc

• error (double) – The relative accepted error of the result

Return type

double

main_axis() → MainAxis

Return type

MainAxis

mode() → OrientationMode

Return type

OrientationMode

param_from_length(length: double, error: double, max_try: int) → double

Compute the parameter for the given arc length.

Parameters

• length (double) – The arc length for which we want a parameter

• error (double) – The relative accepted error of the result

• max_try (int) – Maximum try to reach the error

Return type

double

read_matrices() → BufferConstM44d

Return the readable curve matrices.

Return type

BufferConstM44d

tessellate(start: double, end: double, samples: int, uniform: bool) → Mesh

Builds the line mesh for the sub-part of the curve delimited by start and end. If uniform is true, the curve is sampled with uniform arc-length.

Return type

Mesh

type() → CurveType

Return type

CurveType

write_matrices() → BufferM44d

Return the writable curve matrices.

Return type

BufferM44d