function vertex = perform_normal_displacement(vertex,face,rho,options)
% perform_normal_displacement - perfrom a movement of rho in the normal direction
%
% vertex = perform_normal_displacement(vertex,face,rho,options);
%
% Copyright (c) 2007 Gabriel Peyre
options.null = 0;
simple_mode = getoptions(options, 'simple_mode', 0);
niter = getoptions(options, 'niter', 5);
if simple_mode
normals = compute_normal(vertex,face);
vertex = vertex + rho*normals;
return;
end
% movement along normal
rho = rho/niter;
for k=1:niter
normals = compute_normal(vertex,face);
vertex = vertex + rho*normals;
end