Skip to content

Defining a Roof Ridge

The ridge of building roof can be modeled using the object „Barrier“ with the crowning type „Roof Edge (3D)“ (see Barrier with special crowning).

Entering a Roof Ridge as a Barrier

Proceed as follows:

  • Enter a rectangular building of 10 m height.
  • Select the object „Barrier“ and draw a barrier in the middle and inside the building’s polygon (or enter the coordinates on dialog Geometry of the barrier).

Note

With a barrier representing a roof ridge line and extending to the outside of the building’s polygon, the outside part of the barrier will also cause screening, but this part is not displayed on the 3D-Special view. In the wire-frame view (menu Options|3D-View), however, it is displayed.

  • Open the dialog Barrier and select the crowning type „Roof Edge (3D)“.
  • Enter a height of 20 m via the button „Geometry“.
  • Close the dialog with OK.

Building with Barrier, type "Roof Edge (3D)", height 20 m

  • Press the key combination CTRL+3 to display the 3D-Special view.

House with screening roof ridge

The roof area generated and displayed (in 3D-Special view) using the crowning type „Roof Edge (3D)“ is not a reflecting surface. Reflections at the object „Building“ result - as previously - from the vertical walls of the building only, provided they are reflective and, at least, the first order of reflection is selected (see Reflection Tab).

Assigning a roof bitmap

Now, a texture can be assigned to the roof surface (requires option BMP). Proceed as follows:

  • Select the command Edit Facades from the context menu of the building.

  • Select the symbol „Roof-Bitmap“ from the toolbar to open the dialog Roof-Bitmap.

  • Edit on dialog Roof-Bitmap the bitmap’s coordinates (see Bitmap Dialog Options). When the real dimensions of the texture are known, enter those values starting from the lower left corner at (u, v)= 0, 0).

  • On option „Texture Alignment“ select the option „Gradient“ in order to align the texture starting from the highest point of the roof (i.e. the ridge).
  • Close the dialogs Roof-Bitmap and Edit Facades.
  • Press the key combination CTRL+3 to display the 3D-Special view.

Building with pitched roof and roof texture

The roof texture is also used for the gable walls of the building. However, the eave edge is not a screening edge, only shown in the 3D-Special view.

Defining gable walls

In the following an additional gable wall is entered. Starting with a building having a roof edge already proceed as follows:

  • Activate while in edit mode the building’s polygon using the left mouse button.
  • Hold down the CTRL key and click at the two locations of the building’s polygon intersecting with the (imaginary) extension of the ridge line.

This will insert two additional polygon points.

  • Open the dialog Geometry of the building.
  • Select the option „Height at every Point“ and enter for the additional points - for example - a height of 20 m.

Note

Alternatively, you may of course enter all the coordinates x, y, z on the dialogue Geometry directly.

Entering the height of the gable wall

  • Close the dialog with OK.
  • Press the key combination CTRL+3 to display the 3D-Special view.

Building with gable walls, roof ridge and roof texture

In this case, both, the roof ridge and the eaves edges cause screening.

Other Roof Shapes

In addition to the pitched roof shown in the previous example more roof shapes are possible, such as hipped, gambrel roof or tent shape.

Roof shapes (barriers are dotted lines):top-left: mansard roof, -right: tent (with option „absolute Height at every Point“)bottom-left: gable roof, -right: hip roof

3-Special view of several roof shapes