Exporting a Large Graphic Output Uncrops the Image

Question

I want to export an image exactly as it is shown in the notebook, but when I specify a high image resolution, the image saved to disk does not match what is shown in the notebook (the image saved appears to be an uncropped version of the image). I am running the following code to produce the graphic:

polygonSwirl[
   polygon_: Disk[], thickness_: .8, depth_: 20,   color_: Blue,
   edgeColor_: Black, scalingRate_: .2, xtranslationRate_: .2,
   ytranslationRate_: .2, background_: White, rotationRate_: 1, 
   rotPoint_: {1, 1},  rotModifier_: 5
   ] := Graphics[{EdgeForm[
     Directive[{AbsoluteThickness[thickness], edgeColor}]], color,
    GeometricTransformation[
     polygon,
     Table[
      ScalingTransform[{α/(depth - α)^scalingRate,
                        α/(depth - α)^scalingRate}].TranslationTransform[{-α^
           xtranslationRate, α^ytranslationRate}].RotationTransform[π/(depth - \
α)^rotationRate, rotPoint + rotModifier/α],
      {α, (depth - 1), 1, -1}]
     ],
    }, Background -> background, PlotRangeClipping -> True
   ];

polygonSwirl[
 polygon = Disk[],
 thickness = .4,
 depth = 100,
 color = LightPink,
 edgeColor = Lighter@Purple,
 scalingRate = -.1,
 xtranslationRate = -1,
 ytranslationRate = -1,
 background = LightPink,
 rotationRate = -.999,
 rotPoint = {0, 0},
 rotModifier = 5
 ]

The output shown (I took a screenshot) is

But the image saved to disk when I run this code is different:

 Export["~/Desktop/diskSwirl.png", %, ImageResolution -> 500]  

How do I ensure that the image exported matches what is shown in the notebook exactly? Screenshots do not have high enough resolution for my purposes.

Answer 1

Although you have set the option PlotRangeClipping -> True, you didn't actually specify a PlotRange. This forces Graphics to determine the appropriate range automatically. The default for PlotRange is All, so the result of the Export command is actually correct. The notebook display is not correct.

But if you want the notebook display to show the cropping, and the exported graphic to have the same appearance, you have to override the default by setting PlotRange -> {{-100, 100}, {-100, 100}} (or a similar range).

The fact that the cropping is a bug can be checked by replacing Disk with Rectangle in your code. Then the output in the notebook is not cropped:

So the automatic calculation of PlotRange in the case of transformed Disks is done incorrectly, but for Rectangles it works.