Changes
== Exporting Your Urban Canyon Scene ==
A fully random city scene changes very quickly with few mouse clicks. This is helpful at the beginning when updating the random variables until you get a desirable scene. After that, the random feature may not be useful. [[EM.Cube]] allows you to export your physical structure to a number of popular CAD file formats such as STEP, IGES, STL, <i>etc</i>. The STEP and IGES options export all the solid, surface, curve and point objects. The STL format exports only solid and surface objects as sets of interconnected triangles and ignores all the curve or point objects. This is more suitable for propagation scenes if you don't want to exports all the base location pointspoint radiators. CubeCAD is the module where import and export operations should normally take place. For convenience, you can export your physical structure from any module including [[EM.Terrano]]. However, you can import external files only to CubeCAD.
In the case of stereolithography (STL) file export, [[EM.Cube]] offers two options: ASCII STL and Binary STL. The latter format results in a more compact file. You can generate a triangular surface mesh of objects in CubeCAD. This mesh is what is exported as the STL file. [[EM.Cube]] allows you to control the shape and size of the triangular patches that are used to model your objects. Switch to CubeCAD by clicking its button at the top of the navigation tree. Then, clicking the <b>Mesh Settings</b> [[Image:fdtd_meshsettings.png]] button of the Simulate Toolbar in CubeCAD or use the keyboard shortcut {{key|Ctrl+G}} to open the CAD Mesh Settings Dialog. Change the value of '''Mesh Cell Size''' to 100 units. This will generate very large triangular patches or cells. The parameter '''Mesh Cell Size''' is the counterpart of '''Cell Edge Length''' in [[EM.Terrano]]'s SBR Mesh Settings dialog, which you already encountered in Tutorial Lesson 3.
