Lines in Parallel Coordinates plot not anti-aliased on some hardware

[idea-launch-lab]

The lines in Plotly's parallel coordinates plot (plotly.js) are not appearing smooth or correctly anti aliased. Is there a CSS setting or parameter to control rendering of lines in the plot?

Below is a comparison with native D3 parallel coordinates plot. The plots have been zoomed in a bit. Thanks.

[etpinard]

Hmm. https://rreusser.github.io/plotly-mock-viewer/#gl2d_parcoords doesn't look as blurry to me as your screenshot of the left. Would you mind sharing a reproducible example?

We turn on antialising here, so this report seems a little strange to me. What us could be going on? Maybe @dy could help us out?

Is there a CSS setting or parameter to control rendering of lines in the plot?

Below is a comparison with native D3 parallel coordinates plot.

Our parcoord lines are drawn in WebGL not d3, so CSS won't fix the problem unfortunately.

[alexcjohnson]

@sid-thakur what hardware are you using? I have to say when I look at https://rreusser.github.io/plotly-mock-viewer/#gl2d_parcoords on my mac retina display it looks a bit blurry, as do scattergl plots like https://rreusser.github.io/plotly-mock-viewer/#gl2d_10, whereas gl3d plots look crisp. I hadn't noticed this before but I mostly display plots on my second monitor, which is not as high resolution. Perhaps we need to oversample in addition to antialiasing?

[archmoj]

As a reference point, Mac with FireFox renders like this i.e. without anti-aliasing (Note: although anti-aliasing is requested by the code on some hardware it may not be enabled). To improve this situation, such cases could be detected and doubling glPixelRatio values may help.
https://rreusser.github.io/plotly-mock-viewer/#gl2d_parcoords

[taylorjacklespriggs]

This issue persists on Firefox 68.0.1
https://codepen.io/plotly/pen/QpKOPr

specs
MacOS Sierra 10.12.6
MacBook Pro (15-inch, 2017)
Graphics

• Radeon Pro 555 2048 MB
• Intel HD Graphics 630 1536 MB

[archmoj]

Fixed by #5500