Matlab seems to default to its CPU renderer 'painters' when creating new figures with scattered dots or lines. So
plot3(X,Y,Z);
where X and so on are very large can take a long time (say 1 minute).
Whereas first setting the renderer to the GPU renderer 'OpenGL' is much faster.
set(gcf,'Renderer','OpenGL');
plot3(X,Y,Z);
for the same large X takes 6 seconds.
Awkwardly, plotting a bunch of (disconnected) line segments from vertices in N and edge indices in E in matlab using something like:
plot3([N(E(:,1),1) N(E(:,2),1)]',[N(E(:,1),2) N(E(:,2),2)]',[N(E(:,1),3) N(E(:,2),3)]','k');
or
line([N(E(:,1),1) N(E(:,2),1)]',[N(E(:,1),2) N(E(:,2),2)]',[N(E(:,1),3) N(E(:,2),3)]');
is much slower to render and interact with than to just draw a bunch of degenerate triangles using:
trisurf([E E(:,1)],N(:,1),N(:,2),N(:,3))
This has the added bonus that it seems to throw the renderer automatically in to 'OpenGL' mode.