Thin lines getting thicker

[Wolfgang]

Hello,

I just made an interesting observation: When (re)plotting the very same data set on a XY graph using

PlotXY (,,,,,,,VAL_THIN_LINE,,VAL_SOLID,1,VAL_WHITE)

the line gets thicker every time (it seems to approach a limiting value). In my understanding colors are not transparent in CVI, so I am wondering why plotting the same line 5 times results in a line that is much thicker and indistinguishable from a thick line...?

I am providing a visual impression below: leftmost figure: one plot, middle figure: three plots, right figure: >~ 5 plots

Did I do something wrong?

[Kevin_B. · Accepted solution]

You didn't do anything wrong, you just have anti-aliased plots turned on. Those plots do have semi-transparent edges so that they look smoother, and replotting the same data will cause the plots to "fill out" and exhibit the behavior you're seeing. If you don't want this to happen, disable anti-aliased plots and your data should appear thick (and jagged!) from the beginning but will not get any thicker.  

[Wolfgang]

Thanks! This explains it nicely.

Would you mind and add a sentence such as 'Anti-aliased plots have semi-transparent edges' to the CVI help of ATTR_ANTI_ALIASED_PLOTS? It couldn't harm 😉