Display question about transparent intersected surfaces

Why when I set the intersected surfaces' transparent with 'FaceAlpha', the intersected regions display invalid.

Code:

x=[0:0.01:3];
y=[0:0.01:5];
[X,Y]=meshgrid(x,y);
Z1=X*1.1+Y*1;
Z2=X+Y*1.1;
mesh(X,Y,Z1,'FaceColor','b','EdgeAlpha',0,'FaceAlpha',0.5)
hold on
mesh(X,Y,Z2,'FaceColor','r','EdgeAlpha',0,'FaceAlpha',0.5)

The figure

[Hao Li]

If the FaceAlpha is set as 1, the figure

How can I make the transparent figures correct?

[Jan]

Which Matlab version are you using? Is OpenGL set to hardware or software?

I can reproduce this effect with Matlab online.

[Hao Li]

Thanks for your answer. The version is matlab R2018a, the OpenGL was set to hardware. If I set OpenGL to software, the front and back relationship is wrong, the figure :

Answer 1

[Wentao Du]

This issue is due to the Order Independent Transparency method used by MATLAB called "Depth Peeling." Unfortunately, there are no existing workarounds.

Changing to "opengl" setting to "hardwarebasic" gives a slightly better result, as this triggers the transparency to use an "object sort" method (Typically this is worse than any Order Independent Transparency method). Or you may use the "painters" renderer for the figures created by executing the following:

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

Our development team is looking into addressing this issue and it will be considered for a future release of MATLAB.

Answer 2

[Hao Li]

Thanks a lot for your answer. Yes, when I set the 'renderer' as 'painter' the figure is better.