The Indoor Lego roof template produces different kinds of roofs depending on a roof type selection in the properties dialog. The span roof which is the default dialog selection simply consists of two roof walls arranged in a user-defined angle. Span roofs can be symmetrical or asymmetrical. Consequently, the walls on either side might not have equal height.

Using the radio button in the properties dialog, the roof type can be switched to hipped roof. Hipped roofs consist of four walls with opposing walls that are equally sized. Therefore, hipped roofs are always axially symmetric. As a characteristic element hipped roofs contain front and rear walls which are slightly inclined. The down-tilt of these walls may be specified in the dialog.

Figure 1. The Settings for roofs dialog.

A mouse click on the OK button closes the dialog, creates the roof template and switches to the Drag Mode if all user specifications are correct.

Note: Hipped roofs must fulfil the following conditions:
  • h l = h r
  • l 2 h l tan ( r d )
  • 0 ° < r d < 90 °