Edge lines of objects are not visble

When we import a Google Sketch-up file in unity the Edge lines of objects are not visible. Could you please let me know how can we resolve this problem?

Use a toon shader or crease post effect shader. They aren’t part of the models, but simply the way sketchup shows them.

As suggested we have import the sketchup model in Unity with strokes. Strokes aren’t visible in Unity preview window. Please share the steps to achieve the results.

As hippocoder suggested, you need to use a toon shader or a post-processing effect to get the lines in Unity:

http://unity3d.com/support/documentation/Components/script-Crease.html

http://unity3d.com/support/documentation/Components/script-EdgeDetectEffect.html

http://www.unifycommunity.com/wiki/index.php?title=Outlined_Diffuse_3

I am very new to this software could you please share the steps tp apply the toon shader in Unity