Make legend and triad maintain a 1:1 aspect ratio

[rusu24edward]

Is your feature request related to a problem?

This come from this SRE issue. Terry from LBL would like the triad and legend to maintain 1:1 aspect ratio like the plot when the viewer window is resized.

Additional context

[markcmiller86]

We observed...

• triad skew appears to follow window aspect ratio, not object.
• triad doesn't honor object perspective
  Its conceivable that because triad is part of the annotations layer, it isn't being controlled by the plotted object's view controls.

[aowen87]

We can pretty easily change the behavior of objects like the triad so that they maintain a 1:1 aspect ratio, but this also means that they behave more like the axis actors in general. Most notably, this means that these objects can go out of view.

I've created a simple video that demonstrates these behaviors. In this video, the triad has been altered to maintain a 1:1 aspect ratio by setting its coordinate system to world (like the axis actors). The legend has not been altered here, meaning that it's still using the viewport coordinate system. You can see the difference in behavior pretty easily.

NOTE: the position of the triad in this video is easily adjustable. I just chose something for the demo.

Screen.Recording.2021-04-21.at.9.46.05.AM.mov

Is this an acceptable tradeoff?

[brugger1]

I originally thought it wouldn’t work well, but it actually is quite reasonable. The only concern is if the user zooms in that the triad would go off screen and you wouldn’t see it. The bounding box has the same issue, but it seems like it’s part of the object and therefore behaves as I expect it would.

[aowen87]

I think there's also a ticket somewhere requesting the ability to change the position of the triad and legend. If people really wanted to keep the triad in view after zooming in, they could use that (future) feature to make it happen.

[biagas]

I thought the purpose of the triad was to give some spatial perspective regardless of the zoom/pan of the plot.
If it moves with zoom and pan and can go offscreen, what's the point?

[aowen87]

I thought the purpose of the triad was to give some spatial perspective regardless of the zoom/pan of the plot.

I haven't really thought of the triad in that manner, but maybe I'm in the minority here? I always just assumed it was for directional context only.

Should I move this out of reviewed so that we can discuss this in an upcoming meeting?

[biagas]

Any way to force them to maintain their position in the viewport / prevent them moving offscreen when pan or zoomed?

[brugger1]

Yes, sounds like we should move out of reviewed and re-discuss.

[aowen87]

Any way to force them to maintain their position in the viewport / prevent them moving offscreen when pan or zoomed?

I tried a couple of things earlier, but they all had serious issues. I might be able to translate coordinates from the viewport to the world. I'll give that a try once I finish up this other branch I'm working on.