I think that this is actually relatively recent that itworks (thanks to probably#24522) but it does seem to work now, which is good. (I tested on a machine I hadn't pulled for a while on, and it didn't work, but after pulling it worked)

The second plot (ax1) looks odd, though... but I think that is just an aspect ratio/different scales on the axes problem, (the triangles are drawn essentially to maximize the minimum angle of the triangles, but that computation is done in x-y space, not in screen space so we are squishing some down so that they have smaller angles.) I don't think there is much to do here, as it iscorrect, but it did flag for me as odd.

Thats why I'd prefer the background data was retained, rather than be scrambled.

Further testing has shown thattripcolor doesnot actually behave as we wish it to, issue opened in#27499 to track it.

The axis units are not updated (and in fact I'm pretty sure if we used a different scale (other thanD) the values would be off, it just happens to match mpl's internal model)

As such I'm inclined to not merge this for the time being (until the underlying problems are fixed)

Though perhaps remove theplot calls, since those hide the problem (by setting the axis units) so that this test is largely ready when the time comes. (along with some of the other edits)