Painter's export problem

Dear Matlab central users,

I have created the following patch object:

Faces =[1 2 3 4; 5 6 7 8;9 10 11 12;13 14 15 16]; 

Verts = [-1 1;0 1;0 2;-1 2;0 1;1 1;1 2;0 2;1 1;2 1;2 2;1 2;2 1;3 1;3 2;2 2];

AV_color = [ 1 1 1;0 0.05 1;0.5 0.05 1;1 1 1];

figure

pch = patch('Faces',Faces,'Vertices',Verts,'FaceColor','flat','FaceVertexCData',AV_color,...
            'EdgeAlpha',0,'FaceAlpha',1);

I have prepared patch for painters export using accepted answer in: http://www.mathworks.com/matlabcentral/answers/92720-how-can-i-export-a-figure-containing-a-surface-with-rgb-cdata-to-an-eps-file-using-the-painters-rend

rgb_colors = get(pch,'CData');

[i,map] = rgb2ind(rgb_colors,64);

set(pch,'CData',double(i));

colormap(map);

Unfortunately, black edges appear around each figure upon painters rendering:

set(gcf, 'Renderer', 'painters');

I need the edges to be the same color as the faces. How can this be done?

Thanks,

Phil

Answer 1

[Chad Greene]

Painters does not support transparency. Can you set 'LineStyle' to 'none'?

[Chad Greene]

That is, replace your patch line with

pch = patch('Faces',Faces,'Vertices',Verts,...
'FaceColor','flat','FaceVertexCData',AV_color,...
'linestyle','none');

[Mike Garrity]

Painters does support transparency as of MATLAB version R2014b. Except for the case of exporting to Postscript or EPS because those formats don't support it.

But as Chad said, if you're only using alpha of 0 or 1, then you might be better off using LineStyle=none. I would expect the graphics system to recognize that they're the same, but the LineStyle approach is a bit simpler.

[Phil Dixon]

Yes, Chad's simple solution worked!

Answer 2

[Francesco Carpanese]

A possible solution to fake transparency in .eps file is to properly stack the plots you would like to display, being careful to have the patch in the bottom.

 plot([0,1], [0,1])
h = patch([0. 1. 1. 0.], [max(ylim) max(ylim) 0 0] , 'y', 'Linestyle', 'none',  'EdgeColor', 'none', 'Facecolor', 'g', 'FaceAlpha', 0.2);
% This is needed to bring patch to the buttom and fake the alpha.
uistack(h, 'bottom')
% Need to specify '-painters'
 print('file_test','-painters','-depsc2')
    % code
  ends