Detail steps to import SketchUp models into Unity3d

After the acquisition of SketchUp since Google, SketchUp is a more powerful, and updated much faster speed, here is how to import SketchUp file into Unity3D!
1. When start new SketchUp project, select the engineering units for the Meter (m), if not meters, in the Tools -> Model Info -> Unit within the Format changes to Decimal: Meters can be.

Because it will affect the original SketchUp, so please note that the accuracy is not enough if Precision also need to change to sufficient accuracy, also set the Enable length snapping consistency and accuracy to enable them to correctly perform automatic capture.

2. Select File -> Export -> 3D Model, file format is FBX (only Pro version of SketchUp Caixing). Click Options to modify several options.

Export Options in

Select the Triangulate all faces into all the surface triangles

Select Export two-sided faces are exported to both sides (some flat sides of different materials, it is very important)

Select Export texture maps derived surface texture

Select the Swap YZ coordinates (Y up)

Unit selection Model Unit (the first step if you are right, this election is the same effect Meters)

OK then, you can click Export.

3, In Unity3D, select Asserts -> Import New Asset. Find the exported FBX file. After the file has been imported, select file in Project window. In Inspector window , set FPXImporter/Meshes/Scale Factor to 1. Finally, the model was dragged into the scene and you're done! Enjoy it.