This is fabulous.

What I especially like is the way the model files are organized, which makes it possible to change colors and opacity in Google Earth.

The kmz was probably one lump sum export, with the file structure remaining intact. While we can't do that with the current free plugin furnished here, there is a workaround that will allow the kind of complexity the Boulder model shows.

In developing a SketchUp version of the Salgado exhibit at The Leonardo to replace the earlier version posted here, I'm using the Google Earth plugin for SketchUp to export each subfolder separately. This works because SketchUp references everything in the scene with the same coordinates. The Petrichor exporter for 3DS, by contrast, currently references each separately exported element by local coordinates, so they don't stay together.

That said, I'm really looking forward to the day when SketchUp makes available an onboard kml export tool.

SMcQ