Weird rendering of extruded bezier curves imported from Illustrator CS3

I imported a curve from CS3. Made sure it was closed by hitting ‘c’, then used extrude (the setting, not the e key) to give it depth. The idea being a 3D kind of logo.

IT appears fine, but when I go to render it, the surface has flaws. It isn’t smooth. I’ve tried some tricks and I can’t work out what is wrong. Is there any way to convert the extruded curve into a ‘proper’ 3d shape or something?

Is there something I’m doing wrong?

I just used “The Gimp” plugin to import the .ai file. It appears absolutely fine until render time. The material is not weird at all, just standard 0.8 red with standard everything else for a new material.

Picture attached.


Here is another picture, that shows the render result more clearly.


I typically use the SVG format instead of AI.
In illustrator export your curve as a SVG, then import as SVG. You may have hidden or duplicate verticies that are messing up the render.

Are there multiple curves in the file? If so , you may want to separate them by going into edit mode pressing the L key while over a curve, then the P key to separate them.

Another way to “Stress-Test” your curve it so extrude it and bevel it. These two functions generally will reveal problems in the curve data if any are present. Set the values to extreme numbers and observe the results. Sometimes a stray vertex will be hanging just outside your viewport.

As Atom said, it kinda looks like there’s 2 curves there.
I think, if you’d created one, then accidentally, or purposefully, pressed ALT-D, then you’d have 2 curves there and whatever actions you apply (Extrude, bevel etc) would act on both.
2 things in the same place gives that bitty surface look.