Created attachment 85767 [details] Sample PDF. I have noticed that the square-root expressions in PDFs generated with *TeX can end up looking very odd in okular at various zoom levels, while the same PDF viewed in e.g. the google-chrome PDF viewer are free of this artifact. Attached a sample PDF page where the error is evident. An okular-generated raster image of the artifact is available here: http://i.imgur.com/ybHWkO1.png. Zoom was at 261.31% but is observed also at 350% among others.
Created attachment 85776 [details] rendering
So you mean the one pixel whitespace between the flat part of the root and the initial part of it, right?
Created attachment 85777 [details] Screenshot of rendering of the same document at similar zoom, via google-chrome Yes exactly. For comparison, I have attached a screenshot of a rendering of the same PDF from google-chrome's PDF viewer. I cannot adjust the zoom to the exact same level, but the artifact is not visible at any accessible zoom level in chrome.
Ok, this rendering issues are not Okular's fault since we only show what the poppler library produces. Please open a bug upstream at https://bugs.freedesktop.org