You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: vol2mesh.m
    path of file: ./repos/fieldtrip/external/iso2mesh
    
    the code of the file until where you have to start completion: function [node,elem,face,regions]=vol2mesh(img,ix,iy,iz,opt,maxvo
    
function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
%

if(nargin>=8)
	if(strcmp(method,'cgalmesh'))
		vol=img(ix,iy,iz);
		if(length(unique(vol(:)))>64 & dofix==1)
			error([ 'it appears that you are processing a ' ...
                                'grayscale image. Currently cgalmesher ' ...
                                'does not support grayscale images. ' ...
                                'Please use "cgalsurf" method to mesh a grayscale ' ...
                                'volume. If you are certain to run cgalmesher ' ...
                                'on your data, please set dofix=0 and run this again.' ]);
		end