Prepare for Global Illumination and Render

It is easy to move the calculation from direct light only to a full global illumination scenario considering surface reflectances. We already have a building that serves as an object and it has defined reflectance attributes that were defaults when it was created. The default setting for the side reflectance of an object when created is 50%. We can easily change this using the Surface Edit command.

• Select the Surface Edit button from the Rooms/Objects toolkit.
• Click on the building perimeter, then right click.
• When the dialog opens, click on the shortcut to select all sides from the toolbar as shown below (or ctrl-w).
• Set the reflectance to 20% (0.20).
• Click OK the leave the editor.

Add a ground plane

• From the Rooms/Objects toolkit select the Planar Object command.
• In the dialog, change the Label to “Ground”, change the reflectance to 0.15 (15%).
• Click OK to exit the dialog and draw the polygon.

• Draw the polygon as a simple rectangle around the project.
• It is helpful to turn on Ortho by pressing the F8 key so we can draw straight lines.

Change the calculation mode to Full Radiosity Method.

1. Pull down the menu next to the Calculate button.

2. Select Full Radiosity Method.

Advance to Render mode and calculate.

• Click on the Render tab.
• Click the Calculate button.
• Click on the Plan View button.