Fixing artifacts in a Wren render

[guache]

I'm doing a Wren still-image render of a NURBS object (hidden-line, "technical drawing" style). I get plenty of artifacts. Many outline edges have gaps. In some places small fragments of underlying features show through top surfaces. Are there techniques or parameters (comparable to e.g. "shading quality" or "level of detail") that could be tweaked in a Wren render to eliminate such artifacts?

[old school]

Many times the only way with WREN is to render with thicker lines (double the thickness) at twice the resolution and then scale the output rendered images in COPs back down.

Brute force super sampling.

[guache]

The issue is not the smoothness of the lines (it's fine) but bugs in Wren's outline algorithm. Features that should be hidden (they are in the viewport's hidden-line view) partially "peek through" top surfaces in Wren renders. The outlines of some features (cylinders, NURBS surfaces) have small gaps. Not because the rendered line is jaggy or irregular, but because Wren occasionally gets confused about how to correctly draw the outline of a feature. Basically, I'd need a more accurate outline algorithm, with better spatial resolution, especially on curved surfaces. I wouldn't mind longer render times if I could get rid of the artifacts. I can't render the viewport directly, because I need an outline-only drawing, not a hidden-line wireframe.

[eetu]

Just stabbing in the dark here, maybe try setting the camera clipping planes to fit the object a bit tighter?