Unity - extract plane intersections from mesh polygons

gistfile1.txt

using UnityEngine;
using System.Collections;

public class interspect : MonoBehaviour {

	ArrayList edges = new ArrayList();
	ArrayList points = new ArrayList();
	Plane plane = new Plane(Vector3.up, 0f);

	// Use this for initialization
	void Start () {
	}
	
	void FixedUpdate () {
		Vector3 t = transform.position;
		t.y = Mathf.Sin (Time.time) + 0.1f;
		transform.position = t;
		calculateIntersections ();

	}

	void calculateIntersections() {
		float f = 0f;

		edges.Clear ();
		points.Clear ();
		Mesh m = GetComponent<MeshFilter>().mesh;
		for (int i = 0; i < m.triangles.Length; i += 3) {
			Vector3 p1 = transform.TransformPoint(m.vertices [m.triangles [i]]);
			Vector3 p2 = transform.TransformPoint(m.vertices [m.triangles [i + 1]]);
			Vector3 p3 = transform.TransformPoint(m.vertices [m.triangles [i + 2]]);

			Ray r1 = vectors2ray (p1, p2);
			Ray r2 = vectors2ray (p2, p3);
			Ray r3 = vectors2ray (p3, p1);
			Vector3 i1, i2, i3;

			if (plane.Raycast (r1, out f)) {
				i1 = ;
			}
			if (plane.Raycast (r2, out f)) {
				i2 = true;
			}
			if (plane.Raycast (r3, out f)) {
				i3 = true;
			}

			if (i1) {
				edges.Add(new Ray())
			}
		}
	}

	Ray vectors2ray(Vector3 start, Vector3 end) {
		return new Ray (start, end - start);
	}

	void OnDrawGizmos() {
		Gizmos.color = Color.yellow;
		foreach (Ray r in edges) {
			Gizmos.DrawRay(r);
		}
	}
}