public static Vector3[] ExtractEdgeVertices(Vector3[] vertices, int[] triangles)
{
var verticesLength = vertices.Length;
var trianglesCount = triangles.Length / 3;
var edges = new List <EdgeV2>();
var innerEdges = new List <EdgeV2>();
for (var i = 0; i < trianglesCount; i++)
{
int a = triangles[i * 3];
int b = triangles[i * 3 + 1];
int c = triangles[i * 3 + 2];
var edgeAB = new EdgeV2(a, b);
var edgeBC = new EdgeV2(b, c);
var edgeCA = new EdgeV2(c, a);
AddEdgeOrMoveToInnerEdges(edgeAB, edges, innerEdges);
AddEdgeOrMoveToInnerEdges(edgeBC, edges, innerEdges);
AddEdgeOrMoveToInnerEdges(edgeCA, edges, innerEdges);
}
var currentEdge = edges[0];
var valueOfStart = currentEdge.a;
var currentEndValue = currentEdge.b;
var indexOfEdgeStart = new List <int>();
indexOfEdgeStart.Add(valueOfStart);
indexOfEdgeStart.Add(currentEndValue);
int count = 1;
while (count < edges.Count)
{
currentEdge = edges.Find(e => (e.a == currentEndValue || e.b == currentEndValue) && (e.a != valueOfStart && e.b != valueOfStart));
valueOfStart = currentEndValue;
currentEndValue = currentEdge.a == valueOfStart ? currentEdge.b : currentEdge.a;
indexOfEdgeStart.Add(currentEndValue);
count++;
}
Vector3[] outputVertices = new Vector3[indexOfEdgeStart.Count];
for (var i = 0; i < outputVertices.Length; i++)
{
outputVertices[i] = vertices[indexOfEdgeStart[i]];
}
return(outputVertices);
}
static void AddEdgeOrMoveToInnerEdges(EdgeV2 edge, List <EdgeV2> edges, List <EdgeV2> innerEdges)
{
if (!innerEdges.Contains(edge))
{
if (edges.Contains(edge))
{
innerEdges.Add(edge);
edges.Remove(edge);
}
else
{
edges.Add(edge);
}
}
}
