This is a Pro only feature.
The Export Options dialog box contains options for exporting Epix files.
The Image Size section of the Export Options dialog box contains size and scaling options for your model.
Use View Size
The Use View Size option is used to set your output to the exact dimensions of your SketchUp drawing area.
The width and height fields are used to enter a custom page size for your file.
Resolution (Mac OS X)
The Resolution drop-down list is used to select the resolution for the exported image. For viewing images on the screen, 72-96 pixels/inch is adequate. For printing, you might want to increase the resolution to 150-300 pixels/inch. Remember, high resolution images take longer to generate.
The EPIX section of the Export Options dialog box contains options for the contents of the exported file.
The Export Edges check box is used to maintain the edge rendering style from the drawing area when saving your drawings as an Epix file.
The Export Textures check box is used to maintain textures from the drawing area when saving your drawings as an Epix file.
Export Ground Plane
The Export Ground Plane check box is used to create a ground plane in the Epix file without explicitly modeling a ground in SketchUp.