Computer Graphics Stack Exchange
Computer Graphics Stack Exchange

Questions tagged [bezier-curve]

37 questions
21
votes
5 answers

How to raytrace Bezier surfaces?

I tried this question on math.SE and surprisingly, the answer was "the equations are too nasty, just feed the function it to a numerical root-finder". But if you consider yourself "a graphics guy" like me, and have played extensively with Bezier…
luser droog
  • 1,328
  • 2
  • 12
  • 27
12
votes
2 answers

Hardware-accelerated drawing of curved shapes

How to quickly draw a curved shape? by "quickly" I presume one should use hardware facilities as much as possible by "curved" I mean boundaries defined by either quadratic or cubic Bezier curves by "shape" I mean either a "fat" stroke (i.e. more…
Ecir Hana
  • 1,459
  • 11
  • 20
10
votes
2 answers

Reliable test for intersection of two Bezier curves

How to reliably find out whether two planar Bezier curves intersect? By "reliably" I mean the test will answer "yes" only when the curves intersect, and "no" only when they don't intersect. I don't need to know what parameters the intersection was…
Ecir Hana
  • 1,459
  • 11
  • 20
8
votes
1 answer

Apply distortion to Bézier surface

I am trying to simulate the image warp effect, that is used in Adobe Photoshop. The rectangular image is warped according to a cubic Bézier surface (in 2D, all Z components are 0). Having any Bézier surface, vertical distortion $d \in[0,1]$ can be…
Ivan Kuckir
  • 183
  • 3
8
votes
2 answers

Algorithm to find the center of a Bezier curve

I need to find the center of a Bezier curve to rotate it. I have a list of all points (control points, beginning and end, all points on the curve itself). How would I go about finding it's center?
user4656
  • 81
  • 1
  • 2
7
votes
1 answer

How to calculate matching roundness of two offset rectangles?

I have two rectangles — one with a fill (blue) and one with a stroke (red). The red rectangle is being offset (depending on the stroke width) so that it appears snug and outside the edge of the blue rectangle. This set up works great except when I…
Greg Gunn
  • 93
  • 4
6
votes
1 answer

Silhouette curve for isometric surface of revolution

I am trying to figure out how to convert a flat representation of a curve into the silhouette of a surface of revolution in a isometric projection. In essence in want the planar cut of the surface edge to be converted to the silhouette. Image 1:…
joojaa
  • 8,287
  • 1
  • 22
  • 46
5
votes
1 answer

Bicubic bezier surface from 4 bezier curves

In the program I need to create, the user should specify the hull geometry of an aircraft wing and fuselage using cubic bezier polycurves. But to get to m bezier patch surfaces the user would need to introduce 4 * m additional control points. It's…
ProdoElmit
  • 151
  • 3
3
votes
1 answer

Simple Intersection Algorithm for Ray and 3D Bézier Curves of Varying Thickness

I'm trying to get an algorithm for intersecting a "tube" (a 3D cubic Bézier curve extruded by a possibly-changing radius) with the following required properties: Computes intersections of ray and a 3D cubic Bézier curve. Must not become confused,…
imallett
  • 1,870
  • 10
  • 23
3
votes
2 answers

First steps towards CAD standard curve fitting

I am interested in building a program to accomodate the following workflow: A user begins with an arbitrary vector/CAD shape, which they wish to transfer onto paper without using a printer (there are both realistic and novelty reasons why this…
Will Goldie
  • 33
  • 3
3
votes
2 answers

Checking the correct offset direction for Bezier curve offset

I am implementing Bezier curve offset. My approach is simple: Given the handles, calculate the vectors normal to them Move the handle along the normal vector. If the new curve intersects the old one, reverse the offset direction. etc. I would like…
user1790813
  • 131
  • 1
3
votes
0 answers

Bezier curve : Problem deriving control points from matrix form

This is my first post on this website so i have put in a lot of research to get my point across to everyone as clearly as possible. Based on a question i posted on stack overflow i have successfully derived the control points for an bezier…
Sync it
  • 169
  • 4
3
votes
1 answer

Determining Rational Quadratic Bezier Curve Weights for Circle

I am trying to create a spherical interpolation with 3 points. I'm currently using Quadratic Bezier Interpolation but have been told I should use Rational Quadratic Bezier Curve in order to get a perfectly circular curve. I have tried implementing…
Dr. Pontchartrain
  • 155
  • 4
2
votes
2 answers

What is the mathematics behind inkscape's power stroke path effect interpolator_type and interpolator_beta attributes?

Inkscape has a feature called Power Stroke which is a form of path effect. When you apply it to a stroke you gain 3 control points that allow you to adjust the thickness of the stroke. (I have not yet figured out how to add more control points…
Mutant Bob
  • 151
  • 2
2
votes
1 answer

LoopBlinn Cubic Curve Rendering - Serpentine arteffect

I am trying to implement the Loop-Blinn cubic curve in java using the following source codes GPU-Curve-Rendering and WebCore. Both of them are showing few arteffects and i cannot figure out why. Here are my source code: public class CubicBezier…
codeKhor
  • 61
  • 4
1
2 3