DEM files can contain thousands of points yielding a very detailed, yet very slow, SketchUp model. The CAD files might contain non-standard units, coplanar faces, or inconsistently oriented faces. You can force SketchUp to automatically analyze and repair these issues during the import process.
Points and faces
The Points and faces fields are used to identify the number of points, and subsequent faces, that will be created upon import. The fewer the points and subsequent faces, the better the performance in SketchUp. However, the fewer the points and subsequent faces, the lesser the detail of the imported model.
Generate gradient texture
The Generate gradient texture field is used to apply a gradient texture to the imported DEM model. This texture will be darker in lower areas of the model and lighter in high areas.