Solution #1 Unity Mesh Walls

The solution I have chosen is as follows. Use bezier curve that has 2 control points, these are each end of the line. Then set the rotation based on the tangent at the midpoint. Code shown below.

private static Vector3 CalculateTangent(float t, Vector3 p0, Vector3 p1)
{
    float a = 1 - t;
    float b = a * 6 * t;
    a = a * a * 3;
    float c = t * t * 3;
    return (-a * p0) + (c * p1);
}

public Mesh CalculateMesh()
{
    Mesh mesh = new Mesh();
    List<Vector3> verts = new List<Vector3>();
    Quaternion quaternion = Quaternion.LookRotation(CalculateTangent(0.5f, startPosition, endPosition));
    verts.Add( (quaternion * new Vector3(-widthOffset, 0.0f, 0.0f)) + startPosition );   // 0
    verts.Add( (quaternion * new Vector3(widthOffset, 0.0f, 0.0f)) + startPosition );    // 1
    verts.Add( (quaternion * new Vector3(-widthOffset, height, 0.0f)) + startPosition ); // 2
    verts.Add( (quaternion * new Vector3(widthOffset, height, 0.0f)) + startPosition );  // 3
    verts.Add( (quaternion * new Vector3(-widthOffset, 0.0f, 0.0f)) + endPosition );     // 4
    verts.Add( (quaternion * new Vector3(widthOffset, 0.0f, 0.0f)) + endPosition );      // 5
    verts.Add( (quaternion * new Vector3(-widthOffset, height, 0.0f)) + endPosition );   // 6
    verts.Add( (quaternion * new Vector3(widthOffset, height, 0.0f)) + endPosition );    // 7
    Face[] faces = new Face[] {
        new Face(0, 1, 2, 3),
        new Face(0, 1, 4, 5),
        new Face(0, 2, 4, 6),
        new Face(1, 3, 5, 7),
        new Face(2, 3, 6, 7),
        new Face(4, 5, 6, 7)
    };
    List<int> tris = new List<int>();
    for (int i = 0; i < faces.Length; i++)
    {
        tris.AddRange(faces[i].Tris());
    }
    mesh.vertices = verts.ToArray();
    mesh.triangles = tris.ToArray();
    return mesh;
}