NurbsCurveResult

from panda3d.core import NurbsCurveResult
class NurbsCurveResult

Bases: ReferenceCount

The result of a NurbsCurveEvaluator. This object represents a curve in a particular coordinate space. It can return the point and/or tangent to the curve at any point.

This is not related to NurbsCurve, CubicCurveseg or any of the ParametricCurve-derived objects in this module. It is a completely parallel implementation of NURBS curves, and will probably eventually replace the whole ParametricCurve class hierarchy.

Inheritance diagram

Inheritance diagram of NurbsCurveResult

__init__(*args, **kwargs)
adaptiveSample()

C++ Interface: adaptive_sample(const NurbsCurveResult self, float tolerance)

/**

  • Determines the set of subdivisions necessary to approximate the curve with

  • a set of linear segments, no point of which is farther than tolerance units

  • from the actual curve.

  • After this call, you may walk through the resulting set of samples with

  • get_num_samples(), get_sample_t(), and get_sample_point().

*/

adaptive_sample()

C++ Interface: adaptive_sample(const NurbsCurveResult self, float tolerance)

/**

  • Determines the set of subdivisions necessary to approximate the curve with

  • a set of linear segments, no point of which is farther than tolerance units

  • from the actual curve.

  • After this call, you may walk through the resulting set of samples with

  • get_num_samples(), get_sample_t(), and get_sample_point().

*/

evalExtendedPoint()

C++ Interface: eval_extended_point(const NurbsCurveResult self, float t, int d)

/**

  • Evaluates the curve in n-dimensional space according to the extended

  • vertices associated with the curve in the indicated dimension.

*/

evalExtendedPoints()

C++ Interface: eval_extended_points(const NurbsCurveResult self, float t, int d, buffer result, int num_values)

/**

  • Simultaneously performs eval_extended_point on a contiguous sequence of

  • dimensions. The dimensions evaluated are d through (d + num_values - 1);

  • the results are filled into the num_values elements in the indicated result

  • array.

*/

evalPoint()

C++ Interface: eval_point(const NurbsCurveResult self, float t, LVecBase3f point)

/**

  • Computes the point on the curve corresponding to the indicated value in

  • parametric time. Returns true if the t value is valid, false otherwise.

*/

evalSegmentExtendedPoint()

C++ Interface: eval_segment_extended_point(NurbsCurveResult self, int segment, float t, int d)

/**

  • Evaluates the curve in n-dimensional space according to the extended

  • vertices associated with the curve in the indicated dimension.

*/

evalSegmentExtendedPoints()

C++ Interface: eval_segment_extended_points(NurbsCurveResult self, int segment, float t, int d, buffer result, int num_values)

/**

  • Simultaneously performs eval_extended_point on a contiguous sequence of

  • dimensions. The dimensions evaluated are d through (d + num_values - 1);

  • the results are filled into the num_values elements in the indicated result

  • array.

*/

evalSegmentPoint()

C++ Interface: eval_segment_point(NurbsCurveResult self, int segment, float t, LVecBase3f point)

/**

  • Evaluates the point on the curve corresponding to the indicated value in

  • parametric time within the indicated curve segment. t should be in the

  • range [0, 1].

  • The curve is internally represented as a number of connected (or possibly

  • unconnected) piecewise continuous segments. The exact number of segments

  • for a particular curve depends on the knot vector, and is returned by

  • get_num_segments(). Normally, eval_point() is used to evaluate a point

  • along the continuous curve, but when you care more about local continuity,

  • you can use eval_segment_point() to evaluate the points along each segment.

*/

evalSegmentTangent()

C++ Interface: eval_segment_tangent(NurbsCurveResult self, int segment, float t, LVecBase3f tangent)

/**

  • As eval_segment_point, but computes the tangent to the curve at the

  • indicated point. The tangent vector will not necessarily be normalized,

  • and could be zero, particularly at the endpoints.

*/

evalTangent()

C++ Interface: eval_tangent(const NurbsCurveResult self, float t, LVecBase3f tangent)

/**

  • Computes the tangent to the curve at the indicated point in parametric

  • time. This tangent vector will not necessarily be normalized, and could be

  • zero. See also eval_point().

*/

eval_extended_point()

C++ Interface: eval_extended_point(const NurbsCurveResult self, float t, int d)

/**

  • Evaluates the curve in n-dimensional space according to the extended

  • vertices associated with the curve in the indicated dimension.

*/

eval_extended_points()

C++ Interface: eval_extended_points(const NurbsCurveResult self, float t, int d, buffer result, int num_values)

/**

  • Simultaneously performs eval_extended_point on a contiguous sequence of

  • dimensions. The dimensions evaluated are d through (d + num_values - 1);

  • the results are filled into the num_values elements in the indicated result

  • array.

*/

eval_point()

C++ Interface: eval_point(const NurbsCurveResult self, float t, LVecBase3f point)

/**

  • Computes the point on the curve corresponding to the indicated value in

  • parametric time. Returns true if the t value is valid, false otherwise.

*/

eval_segment_extended_point()

C++ Interface: eval_segment_extended_point(NurbsCurveResult self, int segment, float t, int d)

/**

  • Evaluates the curve in n-dimensional space according to the extended

  • vertices associated with the curve in the indicated dimension.

*/

eval_segment_extended_points()

C++ Interface: eval_segment_extended_points(NurbsCurveResult self, int segment, float t, int d, buffer result, int num_values)

/**

  • Simultaneously performs eval_extended_point on a contiguous sequence of

  • dimensions. The dimensions evaluated are d through (d + num_values - 1);

  • the results are filled into the num_values elements in the indicated result

  • array.

*/

eval_segment_point()

C++ Interface: eval_segment_point(NurbsCurveResult self, int segment, float t, LVecBase3f point)

/**

  • Evaluates the point on the curve corresponding to the indicated value in

  • parametric time within the indicated curve segment. t should be in the

  • range [0, 1].

  • The curve is internally represented as a number of connected (or possibly

  • unconnected) piecewise continuous segments. The exact number of segments

  • for a particular curve depends on the knot vector, and is returned by

  • get_num_segments(). Normally, eval_point() is used to evaluate a point

  • along the continuous curve, but when you care more about local continuity,

  • you can use eval_segment_point() to evaluate the points along each segment.

*/

eval_segment_tangent()

C++ Interface: eval_segment_tangent(NurbsCurveResult self, int segment, float t, LVecBase3f tangent)

/**

  • As eval_segment_point, but computes the tangent to the curve at the

  • indicated point. The tangent vector will not necessarily be normalized,

  • and could be zero, particularly at the endpoints.

*/

eval_tangent()

C++ Interface: eval_tangent(const NurbsCurveResult self, float t, LVecBase3f tangent)

/**

  • Computes the tangent to the curve at the indicated point in parametric

  • time. This tangent vector will not necessarily be normalized, and could be

  • zero. See also eval_point().

*/

getEndT()

C++ Interface: get_end_t(NurbsCurveResult self)

/**

  • Returns the last legal value of t on the curve.

*/

getNumSamples()

C++ Interface: get_num_samples(NurbsCurveResult self)

/**

  • Returns the number of sample points generated by the previous call to

  • adaptive_sample().

*/

getNumSegments()

C++ Interface: get_num_segments(NurbsCurveResult self)

/**

  • Returns the number of piecewise continuous segments within the curve. This

  • number is usually not important unless you plan to call

  • eval_segment_point().

*/

getSamplePoint()

C++ Interface: get_sample_point(NurbsCurveResult self, int n)

/**

  • Returns the point on the curve of the nth sample point generated by the

  • previous call to adaptive_sample().

  • For tangents, or extended points, you should use get_sample_t() and pass it

  • into eval_tangent() or eval_extended_point().

*/

getSamplePoints()
getSampleT()

C++ Interface: get_sample_t(NurbsCurveResult self, int n)

/**

  • Returns the t value of the nth sample point generated by the previous call

  • to adaptive_sample().

*/

getSampleTs()
getSegmentT()

C++ Interface: get_segment_t(NurbsCurveResult self, int segment, float t)

/**

  • Accepts a t value in the range [0, 1], and assumed to be relative to the

  • indicated segment (as in eval_segment_point()), and returns the

  • corresponding t value in the entire curve (as in eval_point()).

*/

getStartT()

C++ Interface: get_start_t(NurbsCurveResult self)

/**

  • Returns the first legal value of t on the curve. Usually this is 0.0.

*/

get_end_t()

C++ Interface: get_end_t(NurbsCurveResult self)

/**

  • Returns the last legal value of t on the curve.

*/

get_num_samples()

C++ Interface: get_num_samples(NurbsCurveResult self)

/**

  • Returns the number of sample points generated by the previous call to

  • adaptive_sample().

*/

get_num_segments()

C++ Interface: get_num_segments(NurbsCurveResult self)

/**

  • Returns the number of piecewise continuous segments within the curve. This

  • number is usually not important unless you plan to call

  • eval_segment_point().

*/

get_sample_point()

C++ Interface: get_sample_point(NurbsCurveResult self, int n)

/**

  • Returns the point on the curve of the nth sample point generated by the

  • previous call to adaptive_sample().

  • For tangents, or extended points, you should use get_sample_t() and pass it

  • into eval_tangent() or eval_extended_point().

*/

get_sample_points()
get_sample_t()

C++ Interface: get_sample_t(NurbsCurveResult self, int n)

/**

  • Returns the t value of the nth sample point generated by the previous call

  • to adaptive_sample().

*/

get_sample_ts()
get_segment_t()

C++ Interface: get_segment_t(NurbsCurveResult self, int segment, float t)

/**

  • Accepts a t value in the range [0, 1], and assumed to be relative to the

  • indicated segment (as in eval_segment_point()), and returns the

  • corresponding t value in the entire curve (as in eval_point()).

*/

get_start_t()

C++ Interface: get_start_t(NurbsCurveResult self)

/**

  • Returns the first legal value of t on the curve. Usually this is 0.0.

*/