We often get requests to import CAD files. Unfortunately, any XML produced from CAD is going to represent a drawing, and not a roof. Those XML files contain information about layers, text styles, leaders, dimensions, and other CAD-specific objects and properties. While it does contain geometry data, the data is not going to be formatted in a way that is meaningful.
For example, if a user were to export a drawing of a house, there would be no way for the app to know what lines are roof lines, and what lines belong to other features of the drawing. If the CAD is 2D, there would be no way to know the pitch. In order for CAD files to have any potential for being importable, standard CAD layers would need to be used (something most PV designers do not do or are even aware of), they would need to be done in 3D (most PV designers who use AutoCAD use AutoCAD LT, which is 2D-only), and the roof would need to be oriented correctly (some designers orient according to the cardinal directions, while others use whatever orientation is the most convenient to draw). Furthermore, all drawings would have to use polygons, not polylines or lines. There are also numerous other subtleties that would negatively impact the software's ability to interpret drawings created by human beings. As much as we would love to import anything and everything, it simply isn't possible.
The XML format we support is called RXF (Roof "Xchange" Format). The format was developed for the exclusive purpose of defining a roof. The file provides detailed information about each roof face including the 3D points, the edge type (ridge, eave, etc), slope, and, potentially, the actual GPS coordinates. Most importantly, it provides the data in a format that is 100% standardized and consistent.