medial-axis | 易学教程

How do I calculate the medial axis for a 2D vector shape?

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问题 I have a 2D shape stored as a path element in an SVG. The shapes consist of Bezier curves and line segments. I also have a set of equally space points along the shape that I am generating using arc length parameterization. How can I use either the SVG or these points to determine the medial axis of the shape? I am using Python, but any sort of pseudocode or algorithm advice would be much appreciated. The following is an example of the types of shapes I am dealing with, and the red dots are my

How do I calculate the medial axis for a 2D vector shape?

阅读更多关于 How do I calculate the medial axis for a 2D vector shape?

How do I calculate the medial axis for a 2D vector shape?

阅读更多关于 How do I calculate the medial axis for a 2D vector shape?

Find medial axis of a polygon using C#

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问题 I've been tasked to figure out how to find the centerline of a polygon. My google searches led me to believe that what I need is called the 'Medial Axis'. Like this: (source: kiev.ua) According to what I've read, what I need can be produced by using a 2D Voronoi diagram construction algorithm for segments. I've found a C# version of the Voronoi algorithm on codeplex (FortuneVoronoi) and after applying my polygon to it, I end up with this: alt text http://www.carbonatlas.com/geonotes/gaia

Delaunay triangulating the 2d polygon with holes

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问题 I want to triangulate the complex (but not self-intersecting) polygon with holes, so that resulting triangles all lay inside the polygon, cover that polygon completely, and obey the Delaunay triangle rules. Obviously, I could just build the Delaunay triangulation for all points, but I fear that some edges of the polygon will not be included into resulting triangulation. So, is such triangulation possible? And if yes, how can I do it? Just in case - I need it to construct the approximation of

Delaunay triangulating the 2d polygon with holes

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I want to triangulate the complex (but not self-intersecting) polygon with holes, so that resulting triangles all lay inside the polygon, cover that polygon completely, and obey the Delaunay triangle rules. Obviously, I could just build the Delaunay triangulation for all points, but I fear that some edges of the polygon will not be included into resulting triangulation. So, is such triangulation possible? And if yes, how can I do it? Just in case - I need it to construct the approximation of polygon medial axis (I hope it can be done via connecting all circumference points of resulting

How to determine if a Delaunay triangle is internal or external?

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问题 I am writing a program that requires a implementation of Medial Axis extraction, of which Delaunay triangulation is a step. External medial axis is unwanted so the corresponding external triangles are intended to be removed. Luckily I came upon a page with a lot of diagrams, also a hint of a method to determine internal and external Delaunay triangles ("based on the broken line perimeter"), but it's just a hint, without detailed explanation. Anybody know the algorithm? EDIT: I forgot