Thread Subject:

Computational Geometry functions

Hi,

I want to be able to do the following in an existing finite element code:

1. Specify an arbitrary closed geometric shape in 2 dimensions (either by drawing, or otherwise).

2. Get a triangular mesh (I know how to use delaunay(x,y) for this).

3. Get the (x,y) coordinates of all boundary points and a boundary connectivity array: every row of this array should contain two columns which hold the index numbers (global node numbers as returned by delaunay) of the two boundary points that are connected by an edge.

I'm able to do this for a circle of known radius because I can use the radius to determine whether a point lies on the boundary or not. But how can I do it for a general shape?

Would the convex hull help?

Thanks
Vivek