After effects shapes are pixelated

A mi me pasaba lo mismo, hacia todo eso que comentaban aqui pero no funcionaba, incluso en la ventana de previsualización estaba la resolucion total, asi que estuve picando donde sea hasta que encontre que tenia desactivado el botón de “BORRADOR 3D”

Is it the 'Quality and Sampling' button?
I've been using AE for 14 years now and this is the first time this stopped me in my tracks. It wasn't that continuous restarization wasn't activated (the usual suspect).
I have a character rig with lots of comps —  that I've used in many projects — and I just couldn't figure out what was different for this one. Turns out, I had accidentally clicked the 'Quality and Sampling' button at some point. I only ever use that for slow motion live action footage so it just wasn't on my radar; I just ramdomly clicked it and it solved the issue after hours of head scratching.

The stupid thing is, I had already checked the character comp by dragging it into new comps multiple times without succes. So this is the weird part: that setting does not just affect the Comp in the Timeline layer but also in the Project Window, so it affects the asset (my ckaracter Comp) in the Project window as well. Wha-huh!

I just got lucky in figuring this out. Hope it helps someone out there.

Before

After

It's probably because you rendering at less than full resolution, I had the exact same problem and I realized I'm looking at my project at a quarter quality at 400% zoom, it comes out clean when you fix the rendering quality.  By now you would have figured it out im sure, who ever else has this problem this is your answer. 

Hi milad0D4D,

Thanks for writing in.

I agree with what Mylenium said. Zooming in into a shape layer would show pixelated results. However, you can scale them up without loosing the resolution.

Let us know if there are any other questions.

Thanks,

Nishu

It never worked any differently. You are zoomed in 800 % and unlike Illustrator AE does not re-rasterize vector content upon zooming for display purposes. All that matters is how it looks at 100% zoom and Full Resolution. there is nothing wrong. You simply have a misunderstanding here.

Mylenium