QuadEdgeTurning

    public void BuildDMesh()
    {
        dmesh = new DMesh3(false,true);

        for (var i = 0; i < points.Length; i++)
        {
            dmesh.AppendVertex(points[i]);
            dmesh.SetVertexColor(i, heightGradient.Evaluate(InverseLerp(-3,7,heights[i])));
        }

        for (int y = 0; y < gridSize.y - 1; y++)
        {
            var rowStartIndex = y * gridSize.x;

            //Left Vertx Heights (ints)
            var topLeft = heights[rowStartIndex + gridSize.x];
            var bottomLeft = heights[rowStartIndex];
            for (int x = 0; x < gridSize.x - 1; x++)
            {
                var quadBottomLeftIndex = rowStartIndex + x;

                //Right Vertex Heights (ints)
                var topRight = heights[quadBottomLeftIndex + gridSize.x + 1];
                var bottomRight = heights[quadBottomLeftIndex + 1];

                //deltaHeights
                var dhtl = DeltaHeight(topLeft, bottomLeft, topRight);
                var dhtr = DeltaHeight(topRight, bottomRight, topLeft);
                var dhbl = DeltaHeight(bottomLeft, topLeft, bottomRight);
                var dhbr = DeltaHeight(bottomRight, bottomLeft, topRight);

                //if (bl == tr && (bl != tl || bl != br))

                if (Abs(dhtr - dhbl ) < Abs(dhtl - dhbr))
                {
                    //bl, tl, tr
                    //tr, br, bl
                    dmesh.AppendTriangle(
                        quadBottomLeftIndex,
                        quadBottomLeftIndex + gridSize.x,
                        quadBottomLeftIndex + gridSize.x + 1);
                    dmesh.AppendTriangle(
                        quadBottomLeftIndex + gridSize.x + 1,
                        quadBottomLeftIndex + 1,
                        quadBottomLeftIndex);
                }
                else
                {
                    //br, bl, tl
                    //tl, lt, br
                    dmesh.AppendTriangle(
                        quadBottomLeftIndex + 1,
                        quadBottomLeftIndex,
                        quadBottomLeftIndex + gridSize.x);
                    dmesh.AppendTriangle(
                        quadBottomLeftIndex + gridSize.x,
                        quadBottomLeftIndex + gridSize.x + 1,
                        quadBottomLeftIndex + 1);
                }

                bottomLeft = bottomRight; topLeft = topRight;

            }
        }
    }

    //returns the total height of 3 verticles
    public int DeltaHeight(int a, int b, int c)
    {
        int max = -100000;
        if (a > max)
            max = a;
        if (b > max)
            max = b;
        if (c > max)
            max = c;

        int min = 100000;
        if (a < min)
            min = a;
        if (b < min)
            min = b;
        if (c < min)
            min = c;


        return Abs(max - min);
    }