Radiosity with Blender By Toussaint Frédéric

Creating a basic scene

In order to learn the best way how to use radiosity, I chose to build a very simple scene. We will make three walls, one floor, one ceiling and a table. Start Blender and build your items as shown on the following picture. Use basic planes for the walls, ceiling and floor, it will ease the calculations, thereafter.

For the floor, we will use the default plane of Blender. Resize it in order to give it a size of 14 grid units (hold the CTRL-KEY all along). In order to speed up the calculation of the radiosity solution, we are about to delete the internal face which as no interest in our case. Edit the floor , select all the vertice (A-KEY) and press the  button until it appears 'off'. To make sure that the visible face is the top face, we will look at the "normals". Press the  button and you will see small blue lines on your object, the location of the line is showing the visible face. If they are pointing the wrong side, select all the vertice (A-KEY) and press the  button. Repeat this step for all the walls and duplicate the floor to create your ceiling (of course, don't forget to flip normals!).