boolean checkCutoff(int v1, int v2, int v3) {
		// never cross a +/- junction with a triangle in the case of orbitals,
		// where we are using |psi| instead of psi for the surface generation.
		if (v1 < 0 || v2 < 0 || v3 < 0)
			return false;
		float val1 = currentMesh.vertexValues[v1];
		float val2 = currentMesh.vertexValues[v2];
		float val3 = currentMesh.vertexValues[v3];
		return (val1 * val2 >= 0 && val2 * val3 >= 0);
	}