I have created the textures with Photoshop having used partially the taken photos, creating brushes and patterns together with the use of a Wacom tablet. The texture of the beak and the one of legs are nearly totally painted using thin brushes in order to simulate the little strips.
I have used four UV Template, one for the body (2k), one for the beak, the leg and the tongue (2k), one for the eye (1k) and one for the cage (2k) From the texture of the color I have done the maps for the specular/bump/diffuse and reflectivity. (Fig.07) Finally with Maya 3D Paint Tool I have fixed some "unavoidable" seams and refined the textures. I have used one shader for each map but the eye, for which I have used two. For the body I have tried to create a slight glow effect to help simulating the feathers. For this I have modified the value "Glow Intensity" in the attributes of the Blinn. (Fig.08) For the beak I have modified the value "Reflection blur" in order to soften the glares of the HDRI (Fig.09) For the eye I have used a Pong shader for the textured part and a transparent Blinn for the external part to which I have applied one circular ramp as map of translucence and specular (Fig.10)
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Lighting & Rendering
I have enabled "depth of field" on the Camera that I have used. In order to establish the focal distance I always use this method: I create a "Distance tool" and put one locator on the point of focus wished (in this case was the bottom part of the beak), subsequently I put the other locator exactly over the Camera that I will have to use for the rendering. I make a "parent" between the locator and the camera therefore that, every time that I will move the Camera, I will have consequent the exact value to insert in the field 'Focus Distance". (Fig.11)
The lighting system is given from an HDRI probe and two lights. One (point light) behind the parrot up with enabled "Use raytrace shadows" and the modified values in order to obtain soft shadows. The other (area light) inside the mouth so to illuminate some parts that otherwise would be remained in shadow with the only use of the other lights sources. I have finally positioned one of my photos as "image plane" of the Camera, just to have a credible background behind the cage, even if blurred because of the DOF.
The rendering settings are those that you see in the grab (Fig.12). Final Gather and sampling values are high enough to avoid the grain effect given by the DOF, but not exaggerated considering an output image of 4000x2250. Once obtained the final image (approximately 4 hours with a Pentium Quad-core) I have enhanced the contrast in Photoshop.
I hope this brief tutorial could be in some way useful and to have satisfied some curiosity about my working way. Many Thanks for this opportunity and to everyone reading this article.