Define a new interior project, or add a new room to your project. Choose a polygonal room shape.

After that dialog, you will be in 2D edit mode where you can define the room shape and the length of each wall.

You can end this 2D edit mode with a double click or the  "ENTER"  key. A new menu opens and you can extrude your scene either to the Z-, or X-axis.

This procedure also works for exterior projects (without extrusion of the walls).

This option makes it possible to construct rooms both off of a floor plan and from a cross-section. 

This procedure works both for interior rooms and for outdoor projects (there it is not necessary to extrude the walls).

Example 1: extrude scene to Z-axis

Selecting the room type.

  2D editing mode. 

Setting the extrusion direction.

 

If you want to add or remove corner points, select the scene and find the "Insert vertex" or  "Delete vertex" command in the menu "Start".

From left to right: clicking on the corner point to move it, clicking on the blue line between two corner points to add a new point.

Note: During the drawing command, you can change the snap grids or use zoom functionalities. The backspace key will remove the last corner point.

Example 2: extrude scene to X-axis

Define a new interior project, or add a new room to your project. Choose a polygonal room shape. 

After that dialog, you will be in 2D edit mode, where you can define the sectional room shape and the height of each wall. 

You can end this 2D edit mode with a double click or the  "ENTER"  key. A new menu opens and you can extrude your scene to the X-axis.

Selecting the room type

Editing the polygon points in 2D view.

Setting the direction of extrusion.

Radiosity rendering.                                                                                                                 

Ray tracing rendering.