void MakeCornerBridge(GridMesh mesh, Vector3 v0, GridDirection bridgeDirection)
    {
        Vector3 b0 = GridMetrics.GetBridge(bridgeDirection.Previous());
        Vector3 b1 = GridMetrics.GetBridge(bridgeDirection.Next());

        mesh.AddQuad(v0, v0 + b0, v0 + b0 + b1, v0 + b1);
        if (mesh.useUVCoordinates)
        {
            mesh.AddQuadUV(0f, 0f, 0f, 1f);
        }
    }
    void MakeBridge(GridMesh mesh, Vector3 v0, Vector3 v1, GridDirection bridgeDirection)
    {
        Vector3 bridge = GridMetrics.GetBridge(bridgeDirection);
        Vector3 e0     = v0 + bridge;
        Vector3 e1     = v1 + bridge;

        mesh.AddQuad(v0, e0, e1, v1);
        if (mesh.useUVCoordinates)
        {
            mesh.AddQuadUV(0f, 0f, 0f, 1f);
        }
    }