Exporting graphics to PDF - huge file

I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with ParametricPlot3D[{r Cos[θ], r Sin[θ], r^2}, {r, 0, 1}, {θ, 0, 2 π}] then context-click on the graphics and select Save Graphic As ..., and save it as PDF. The resulting PDF is 5MB large! When I include it in my LaTeX file it takes a long time to compile a

[y8ttyan]

でプロット部分をラスタ画像，軸やラベルをベクター画像にしてる人