Drawing n number of circles one on top

Unity Engine
1

How to draw n (n < 100).number of circles one on top like attached image with good performance. I am using transparent shader and getting very low fps after 15 circles. Can someone help me to do this?

Thanks

1872671--120340--OverdrawCircles.png

2

You could draw the circles into a single texture. http://wiki.unity3d.com/index.php?title=TextureDrawCircle

–Eric

3

I wants filled circle grow from radius 0 to 1,time t = 0 and next one from 0 to .9 , t= 5 and next one from 0 to .8f ,t = 10 and so on. Can we do the same with SetPixel method without aliasing issues. Is this really expensive method?. any other way to achieve the same?

Thanks
Sabin