bezier

Bezier贝塞尔曲线的原理、二次贝塞尔曲线的实现

由 拜拜、爱过 提交于 2020-01-06 04:29:55
Bezier曲线的原理 Bezier曲线是应用于二维图形的曲线。曲线由顶点和控制点组成，通过改变控制点坐标可以改变曲线的形状。 一次Bezier曲线公式： 一次Bezier曲线是由P0至P1的连续点，描述的一条线段 二次Bezier曲线公式： 二次Bezier曲线是 P0至P1 的连续点Q0和P1至P2 的连续点Q1 组成的线段上的连续点B(t)，描述一条抛物线。 三次Bezier曲线公式： 二次Bezier曲线的实现 #include <vector> class CBezierCurve { public: CBezierCurve(); ~CBezierCurve(); void SetCtrlPoint(POINT& stPt); bool CreateCurve(); void Draw(CDC* pDC); private: // 主要算法，计算曲线各个点坐标 void CalCurvePoint(float t, POINT& stPt); private: // 顶点和控制点数组 std::vector<POINT> m_vecCtrlPt; // 曲线上各点坐标数组 std::vector<POINT> m_vecCurvePt; }; #include <math.h> #include "BezierCurve.h" CBezierCurve:

AS3- create a loopable random path in 3D space

由 柔情痞子 提交于 2020-01-06 04:12:05
问题 I'm trying to optimize a 3d demo by populating a lookup table with 3d points(Vector 3D http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/geom/Vector3D.html) which I will then access later on. These 3D points will define a random and loopable path in 3D space. Does anyone know a way of achieving this? I was thinking modifying the Greensock Bezier tween to create a bezier in 3d space, and then somehow grabbing the xyz values of the resulting tween. 回答1: Ok, you'll need to

Bezier curves draw stretched ellipses in HTML5 canvas

由 ぃ、小莉子 提交于 2020-01-05 07:37:22
问题 This method for drawing ellipses appears to be clean and elegant: http://www.williammalone.com/briefs/how-to-draw-ellipse-html5-canvas/ However, in testing it, I found that the resulting ellipses were stretched. Setting width and height equal, I got ellipses that were about 20% taller than wide. Here's the result with width = height = 50 : To make sure that the problem was with the method itself, I tried changing the algorithm so that all the points used for the Bezier curves were rotated 90

Draw a curve (bezier curve) between two lat long points on google maps android

由 ⅰ亾dé卋堺 提交于 2020-01-04 08:55:43
问题 I want to draw a curve (Beizer curve) between two lat-long points. Currently i am referring this post (code is in javascript). Code to get curve points using cubic bezier equation private void drawElementsOnMap(LatLng init, LatLng end) { mMap.addMarker(new MarkerOptions().position(init)); mMap.addMarker(new MarkerOptions().position(end)); LatLngBounds.Builder bc = new LatLngBounds.Builder(); bc.include(init); bc.include(end); mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bc.build(), 100

Draw a curve (bezier curve) between two lat long points on google maps android

由 為{幸葍}努か 提交于 2020-01-04 08:55:25
问题 I want to draw a curve (Beizer curve) between two lat-long points. Currently i am referring this post (code is in javascript). Code to get curve points using cubic bezier equation private void drawElementsOnMap(LatLng init, LatLng end) { mMap.addMarker(new MarkerOptions().position(init)); mMap.addMarker(new MarkerOptions().position(end)); LatLngBounds.Builder bc = new LatLngBounds.Builder(); bc.include(init); bc.include(end); mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bc.build(), 100

How to determine endpoints of Arcs in GraphicsPath PathPoints and PathTypes arrays?

由 我只是一个虾纸丫 提交于 2020-01-03 03:56:06
问题 I have the following PathPoints and PathTypes arrays (format: X, Y, Type): -177.477900, 11021.670000, 1 -614.447200, 11091.820000, 3 -1039.798000, 10842.280000, 3 -1191.761000, 10426.620000, 3 -1591.569000, 10493.590000, 3 -1969.963000, 10223.770000, 3 -2036.929000, 9823.960000, 3 -2055.820000, 9711.180000, 3 -2048.098000, 9595.546000, 3 -2014.380000, 9486.278000, 3 Here is what this GraphicsPath physically looks like. The 2 Arcs are very distinguishable: I know that this GraphicsPath

Nearest point on a quadratic bezier curve

由 与世无争的帅哥 提交于 2020-01-02 08:03:19
问题 I am having some issues calculating the nearest point on a quadratic curve to the mouse position. I have tried a handful of APIs, but have not had any luck finding a function for this that works. I have found an implementation that works for 5th degree cubic bezier curves, but I do not have the math skills to convert it to a quadratic curve. I have found some methods that will help me solve the problem if I have a t value, but I have no idea how to begin finding t. If someone could point me

Drawing Bezier curves in MonoGame (XNA) produces scratchy lines

由 ≯℡__Kan透↙ 提交于 2020-01-02 05:18:35
问题 I recently got into using MonoGame, and I love the library. However, I seem to be having some issues with drawing bezier curves The result that my code produces looks something like this Look bad, no? The lines aren't smooth at all. Let me show you some of the code: //This is what I call to get all points between which to draw. public static List<Point> computeCurvePoints(int steps) { List<Point> curvePoints = new List<Point>(); for (float x = 0; x < 1; x += 1 / (float)steps) { curvePoints

Calculation of cubic Bézier with known halfway point

由 笑着哭i 提交于 2020-01-02 04:48:06
问题 I know: The control points a and d (start and end point of a 2D cubic bezier curve) The slopes a->b, c->d, and b->c (b,c the other control points) Where the halfway point of the Bézier curve is. Now, given this information, what is the formula for the positions of control points b and c ? 回答1: I know this question is old, but there is no correct or complete answer provided, so I thought I'd chime in with a solution. Note that David's calculations contain several errors and his solution is

LibGDX guidance - sprite tracing 2D infinite random bezier curve

由 耗尽温柔 提交于 2020-01-01 17:09:25
问题 I've been able to apply a smooth animation to my sprite and control it using the accelerometer. My sprite is fixed to move left and right along the x-aixs. From here, I need to figure out how to create a vertical infinite wavy line for the sprite to attempt to trace. the aim of my game is for the user to control the sprite's left/right movement with the accelerometer in an attempt to trace the never ending wavy line as best they can, whilst the sprite and camera both move in a vertical
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