I'm trying to make a 3D bottle using 3D revolve but I keep on producing models with missing parts. I'm using CS6 on OS X and the settings are shown on the image below. I tried two variations: the path on the far right is closed, it is a complete shape; the one on its left is an open path without the straight line on the right. They both produce the same result as shown. I've redrawn the shapes a few times and 'united' them using pathfinder just to make sure, but it didn't help. Thanks in advance for any insight into this!
Change some 3D property by a minute amount.
That is..... add .2° to one of the rotation fields, add 1 to the perspective, etc. until missing faces appear.
As far as I'm aware, it just takes these minute adjustments until AI decides to draw all the faces. It's annoying, infuriating, and has been a problem for more than 10 years.... Adobe doesn't update the 3D effect, sadly.
I have tried to replicate this problem using Illustrator CC 2107, but I can't, no matter how much I rotate the object. I suspect this may be a problem that Adobe has partially fixed in the more recent versions.
From time to time however, I have noticed that the 3D Revolve filter doesn't like extreme curves between two anchors, so perhaps if you were to add one anchor point within the curve it might help.
For example, add an anchor point as shown here: