plotting – Why the exported result is different from the evaluated result

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Why the exported result is different from the evaluated result?
How to set to make them the same!

Here’s the code, It needs the package MaTeX. It’s Ok, If you don’t use this package, just make sure the text remain the same size when evaluating and exporting.

(Gamma) = 7/18 (Pi);
a1 = Graphics3D({Opacity(0.4), LightBlue, Sphere(), Opacity(1), Black,
     Thick, Line({{-1, 0, 0}, {1, 0, 0}}), 
    Line({{0, 1, 0}, {0, -1, 0}}), Line({{0, 0, -1}, {0, 0, 1}})});
a2 = ParametricPlot3D({Cos(t), Sin(t), 0}, {t, 0, 2 (Pi)}, 
   PlotStyle -> {Black, Dashed});
a3 = ParametricPlot3D({0, Cos(t), Sin(t)}, {t, -(Pi)/2, (Pi)/2}, 
   PlotStyle -> {Black, Dashed});
a4 = ParametricPlot3D({Cos(t), 0, Sin(t)}, {t, -(Pi), (Pi)}, 
   PlotStyle -> {Black, Dashed});
data = Table({0, Cos(t), Sin(t)}, {t, 3 (Pi)/2, 5 (Pi)/4, -0.01});
a5 = Graphics3D({Green, Arrowheads(0.035), Arrow(Tube(data, 0.01))});
data = Table({0, Cos(t), Sin(t)}, {t, (Pi), 1.5 (Pi)/2, -0.01});
a6 = Graphics3D({Green, Arrowheads(0.035), Arrow(Tube(data, 0.01))});
data = Table({0, Cos(t), Sin(t)}, {t, (Pi)/2, 3 (Pi)/2, 0.01});
a7 = Graphics3D({Green, Tube(data, 0.01)});
a8 = Graphics3D({Green, Sphere({0, -1, 0}, 0.05)});
a9 = Show({a1, a2, a3, a4, a5, a6, a7, a8}, BoxStyle -> Opacity(0), 
   ViewPoint -> {(Pi), -1.4 (Pi), (Pi)/1.5});
data = Table({-Cos(t) Sin((Gamma)), Cos(t) Cos((Gamma)), 
    Sin(t)}, {t, (1.5 (Pi))/2, (1.75 (Pi))/2, 0.01});
b1 = Graphics3D({Green, Arrowheads(0.035), Arrow(Tube(data, 0.01))});
data = Table({-Cos(t) Sin((Gamma)), Cos(t) Cos((Gamma)), 
   Sin(t)}, {t, (2 (Pi))/2, (2.25 (Pi))/2, 0.01}); b2 = 
 Graphics3D({Green, Arrowheads(0.035), 
   Arrow(Tube(data, 0.01))}); data = 
 Table({-Cos(t) Sin((Gamma)), Cos(t) Cos((Gamma)), 
   Sin(t)}, {t, (Pi)/2, (3 (Pi))/2, 0.01}); b3 = 
 Graphics3D({Green, Tube(data, 0.01)});
data = Table({0.2 Sin(t), -0.2 Cos(t), 0}, {t, 0, (Gamma), 
   0.01}); b4 = 
 Graphics3D({Red, Arrowheads(0.015), Arrow(Tube(data, 0.008))}); b5 = 
 Graphics3D({Red, 
   Tube({{0, 0, 0}, {Sin((Gamma)), -Cos((Gamma)), 0}}, 0.008)});
b6 = Rasterize(
  Show({a9, b1, b2, b3, b4, b5}, ImageSize -> {1000, 1000}), 
  RasterSize -> 3000)

c1 = Graphics(
   Text(MaTeX(
     TeXForm(StringTemplate("(Gamma) = ``(Degree)")(
       Floor((Gamma) 180/(Pi)))), FontSize -> 30), {0, -0.1}));
c2 = Canvas(c1, FrameStyle -> False, PlotRange -> {{-1, 1}, {-1, 1}}, 
  Background -> b6, ImageSize -> {1000, 1000})
Export("带闭合路径的庞加莱球   " <> 
   DateString({"(Date ", "ISODate", " Time ", "Hour", "-", "Minute", 
     "-", "Second", ")"}) <> ".pdf", c2) // SystemOpen
````