Texturing the table
The table is a simple plane and I added the following texture for the colour and I also used it to apply some bump:
The lighting is a single HDRI angular map and nothing else.
Yaf(a)ray provides 4 materials types: glass, glossy, coated glossy and shinydiffuse. I mainly used shinydiffuse for non reflective materials like paper, glass for the transparent plastic and coated glossy for the metal shaders.
The bump value (Nor slider in Blender) should be set like in Yafray, usually these values are lower then the values defined using the Blender Internal renderer. I used values from 0.003 to 0.1 for noise textures and 1-2 for the splitting areas and the small squares on the metallic sheet but I set it to 5 for the back casing number.
Here are some screen shots for the material setting in the Yaf(a)ray script:
For the rendering I used the Revision 175 of Yaf(a)ray. As it is not yet fully integrated with Blender, the parameters should be set in both Blender and Yaf(a)ray. The lights, the materials and the rendering settings should be defined through the Yaf(a)ray script whereas the camera, the image textures (colour and bump) and the HDRI image are defined in the Blender UI.
I selected the Path tracing method as it is a full GI engine with Radiosity, I may have used the Photon mapping method which probably produced something equivalent. I also rendered the scene with the Direct lighting method to get a more contrasted image but without GI and then faster. The two images will then be mixed together into Photoshop.
The rendering time was about 22 hours for the Path tracing (After some tweaks I got more or less the same result as a previous rendering which took about 40h) and about 7 hours for the Direct lighting. The image size is 1600 x 1200.
Machine used: Windows XP, Intel Core 2 duo 2.6, 2 GB Ram
The Post Processing
I used Photoshop for the post processing; I loaded the 2 rendered images into separate layers. Playing with the eraser over the image rendered with the Path tracing method I let appear the image rendered with the Direct lighting method in the shadowed regions to make them more contrasted. I then created the DOF using the Gaussian Blur filter. Yaf(a)ray, as well as Yafray can produce the DOF, but it increases the rendering time and I had a better control on the DOF during the post processing.
Thanks for reading this "Making of", I hope it was helpful.