Mac OS X QuickLook supports the Collada interchange format with .dae file extension out of the box.
There is CaniVIZ 3D Preview available for 59$ and there are free standalone viewers for CAD/3D files like eDrawings Viewer. There’s even a plug-in for .stl files popular in 3D printing.
Is there a free or cheap (< 5 USD) QuickLook plug-in, maybe part of a viewer application, that is capable of formats like .dxf/.dwg, .3ds/.max, .obj, .skp/.kmz?
How hard would it be to write or adapt an existing one? SketchUp/3D Warehouse .kmz files, for instance, are .zip archives that contain a .dae file among other stuff. Also, there’s a FOSS project, Meshlab, that should contain the required parsing code for a lot of formats.
Best Answer
Try Graphic Converter, at least this one works for previewing the .skp files. In the free version you just need to wait around 30s to use the apps.
In some forums, there is said that to generate quicklook plugins, the developer of the apps needs to open up the source code in how their apps generate the files to display. Even maybe if someone is able to reverse engineering the apps to get the source code, there is still problems in terms of licensing. Unless otherwise the code used is under GNU license.