Sketchup shows the black drawing lines, plus the surfaces. SH3D only shows the surfaces. If you make a render in Q3 or Q4 the model will get some shadows and it will look better.
I even claim that the model looks better without the black lines, much more realistic. I set these edges to invisible because something like these black lines I have never seen in real life...
Thanks guys, you're right it's better without black lines
But sometimes i want them (-:
I found a solution, i open the skp file with sketchup and I select "export edges" in the collada file options