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Questions tagged [bspline]

A B-spline (basis spline) is the generalization of the Bézier curve which has minimal support with respect to a given degree, smoothness, and domain partition.

A B-spline (basis spline) is the generalization of the Bézier curve which has minimal support with respect to a given degree, smoothness, and domain partition.

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extract arc/circle definition from bspline

I must decode STEP cad file in which a 3d circle can be defined as a spline. I want being able to decode that the spline is an arc or a circle. At first I have the step B_SPLINE_CURVE_WITH_KNOTS element. #307 = B_SPLINE_CURVE_WITH_KNOTS ( 'NONE',…
sancelot
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Finding sections of a NURBS curve that has a curvature over a predefined value

I am trying to find the the sharp corners of a NURBS curve. For this problem I define a limit curvature. I am trying to find the sections on the curve that has a curvature higher then this value. One option is to interpolate over the curve and…
Hakan Kapson
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Gaussian-like smoothing using b-spline basis function

To do a low-pass filter, I have used a Gaussian kernel, then do a convolution with this kernel to have the smoothed version of my image. Since the spline basis function tend to give a sharper cut-off, I would like to build a spline 2d kernel. Does…
nguyen van linh
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scipy.interpolate.splrep giving incorrect interpolation for b-spline

I'm using the following code: x = [80, 85, 90, 95, 100, 105, 110, 115] y = [0.31976258043267208, 0.31718670335264199, 0.30116311412953689, 0.29687766899837931, 0.29802720516866577, 0.30707962224836099, 0.32328422706655086,…
user1387717
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interpret result of scipy.interpolate spline fit

I have some data points which I like to approximate with a cubic b-spline fit. In an other program, I like to interpolate some points using only the fitted knots and coefficients. This means that I need to write the code to evaluate a point given…
user3611765
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B spline Basis Matrix Program

I am implementing an algorithm to generate basis function for bsplines using the following link: http://www.cs.mtu.edu/~shene/COURSES/cs3621/NOTES/spline/B-spline/bspline-curve-coef.html I should get a tridiagonal system on solving the system of…
user3133623
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B-Spline recursive definition in C#

I'm trying to implement the recursive definition for B-Splines in c# but I can't get it right. Here's what I've done: public static Double RecursiveBSpline(int i, Double[] t, int order, Double x) { Double result = 0; if (order == 0) { …
Gábor Birkás
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Formula to calculate the control point from three known points on a D3 "basis" curve

I have a curve generated by a D3.js line generating function with interpolate set as "basis". The problem is that the line generated only touches the first and last point given into the line generating function and does not pass through the ones in…
BruceHill
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Thrust vector transformation involving neighbor elements

I have a vector, and I would like to do the following, using CUDA and Thrust transformations: // thrust::device_vector v; // for k times: // calculate constants a and b as functions of k; // for (i=0; i < v.size(); i++) // v[i] =…
user1522407
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gluLookAt Issues

I've been trying to create a roller coaster simulator in OpenGL which uses a series of gluLookAt calls to make the camera 'ride' the roller coaster. The coaster itself is based on a b-spline curve with control points in the coords array. b0(u),…
JMcMinn
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Are there any 3D modeling libraries written in java

I've found OpenNurbs, but it's written in C++, I need a 3D modeling library in java. What I really need is a B-Spline class which can be constructed with some interpolation points.
bitcold
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What difference is between a Coons B-spline and a Bezier Spline?

What is the difference between a Coons B-Spline and a Bezier Spline? Should I say "Bezier Spline" or "Bezier B-spline"? What is the right term? I've read some articles about it, but they usually discuss both of these types of spline together, so I…
user1097772
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Maintaining "upvector" in a BSpline

My current task: To extrude a shape along a MOVING bspline. Each control point on the bspline consists of a position, and an "up" vector Initially, people using my code will establish their bsplines like this (green dots/lines are the position and…
KiraHoneybee
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Defining BSpline in SciPy knowing its degree, control points, knots, and weights

I am trying o re-create a spline curve defined in STEP geometry (entity "B_SPLINE_CURVE_WITH_KNOTS") for later evaluation using SciPy, knowing its degree, control points, knots, and weights. If needed,I could also have spline starting and ednding…
Oki
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Understanding scipy b-spline base interval

I want to use scipy's b splines. However, in their examples they say that compared to the naive implementation, "outside of the base interval results differ". I don't understand what the base interval here is. I need the behavior of the naive…
Luca Thiede
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