When you import Google warehouse files (.kmz) or other Collada files (.dae) into Photoshop Extended, materials look like they haven't been imported with the model. Or, models are incomplete or invisible.
Install the 3D Invert Opacity.jsx script into your Scripts folder, so it is accessible via the File > Scripts menu in Photoshop.
A number of 3D Collada files (.kmz, .dae) have the Opacity materials setting inverted. For examples, materials that are 100% opaque are imported into Photoshop as 0% opaque (fully transparent),. Likewise, materials that are 80% opaque are imported as 20% opaque, or partially invisible.
This issue occurs when Collada exporters write their transparency modes in a certain way, which Photoshop does not recognize, and therefore cannot correct.