Meet Dr. Hugo Fancy. This character is a proof of concept based on the main character of a live action television pilot I did some visual effects work on called The Undercurrent, created by Adam Behr.
It is a personal project of mine to recreate this pilot as a 3D animation. The style of the pilot itself is a dark comedy and on the 3D side of things, I wanted a highly realistic look in the environment, lighting, and textures, while having toon-like characters.
My tool of choice for this is Blender using Cycles to render, but since Cycles does not yet support hair, I had to render the hair with Blender Internal and composite the two together. There are a few serious technical problems I have encountered while mixing Cycles with Blender Internal, which is why I have decided to put this project on hold until Cycles is developed just a little more to include hair rendering among other things which are scheduled to be started after the 2.65 release.
The first problem I encountered was with the lighting of the hair. The shadow cast from the hair onto the head had a light fringe where the BI deep shadow met the Cycles shadow. This was not only unrealistic but very ugly. (The rendering on the left was composited without the hair casting a shadow on the head)
An other glitch I encountered was what seemed to be a problem with matching up the FOV of Cycles and BI. I used an extremely low angle FOV on the camera to create more of an orthographic view. This created a transparent gap of about 2 pixels between the hair and the head. When the FOV was increased again, the hair and head matched properly. I am not 100% sure, but I think this may be due to a slightly different algorithm in Cycles for calculating the FOV.
For those of you interested in how I composited the BI hair with the Cycles rendering, Here is a screenshot of the node tree.