Matlab plot saved as (vector) EMF but rendered as raster - matlab

Question

I have Matlab code that produces an array of subplots that looks like this:
When I save this as an EMF file (normally a vector format) and insert in Powerpoint or view with Inkscape, then zoom in closely on the image, it looks pixelated, and clearly made up of a single encapsulated object as opposed to many small graphical objects:
This is very surprising to me, as I have for a long time been exporting Matlab plots as EMF and integrating those into Powerpoint slides, in order to build there more complex graphs that, as vector graphics, would print well at any size. These imported EMFs would also scale well and look smooth regardless of how much I zoomed into them in Powerpoint.
Can anyone guess why it is that on this occasion, this plot is not saved as a vector graphics but is instead (as it seems) rendered as raster? The code that produces this figure (based on the Matlab commands subplot, line, and scatter) is rather long/inelegant, but I can give details or simplify, if required to find a solution. Thanks!
Other similar threads on this site have not helped fix this.

Answer 1

I believe I have encountered this issue before. If it is the same as the issue I was facing, it is to do with the renderer being used to save the plot. Although it should automatically select the painters renderer when exporting to vector files, I have had instances where it used the openGL renderer instead, which results in bitmaps being used. I'm not entirely sure why this happens -- it might be the case that for particularly complicated figures, it reverts to openGL to avoid obnoxiously large or complicated vector files.
If you are using the print command, you can force it to use the painters algorithm as follows:
print('-painters',...)
if you're saving using File>Save As..., I believe setting the renderer for the figure should work:
set(figure_handle,'renderer','painters');
For explanation, per the MATLAB documentation:
-opengl' — OpenGL renderer. Use this renderer when saving bitmap images. OpenGL produces a bitmap image even with vector formats, which might limit the extent to which you can edit the image in other applications.
'-painters' — Painters renderer. Use this renderer when saving vector graphics files. If you save to a vector graphics file and if the figure RendererMode property is set to 'auto', then print automatically attempts to use the Painters renderer. If you want to ensure that your output format is a true vector graphics file, then specify the Painters renderer. For example:
print('-painters','-deps','myVectorFile')
If you do not specify the renderer, then print automatically uses the appropriate renderer to produce the output format requested. However, if you set the Renderer property for the figure, then print uses that renderer when generating output.
EDIT: Another option is to use the Copy Figure command (Edit > Copy Figure) -- this should copy the figure as an EMF file, and should obey the figure's renderer settings.