Giovanni Lorenzo Bernini is by far my favourite sculptor from history. I love his subjects' expressions and masterful forms. His bust of Constanza Bonarelli is one of his smaller pieces that I greatly admire, and for that reason I chose to create it digitally.
I gathered as much reference material as I could, with Flickr.com being a great source for this job - people uploading their images from visiting museums is a great way to get strange and often un-photographed angles of a piece.
I approached the project by starting out with a 2D sketch; I believe this can burn the forms and details of an object into your memory, which helps me immensely when I come to the sculpting stages. Using just a simple pencil brush in Photoshop, I sketched out and painted the bust, checking proportions and measuring details as I went along (Fig.01).
In 3d Studio Max, I created a simple base mesh using edit polys and Max's poly modelling tools - nothing too complex, just clean and with enough loops and detail to sculpt all areas of the model. I exported the base and took that into ZBrush where the digital sculpting began.
I don't like to use any image planes or background images, as the camera distortion often leads you to wonder what the proportions should actually look. To me, they encourage tracing and end up not giving as many benefits as sculpting from reference photos. I let my mind spend as much time as needed analysing the forms and structure of the bust, placing strokes, pushing and pulling geometry where I felt it was necessary.
The process was mostly completed using the Move and Clay brushes in ZBrush. The Clay brush gives you the freedom to pull the surface of the model in small layers, just as in real life where we'd add small layers of clay to build up the surface. This is my favourite and most used addition to the latest release of ZBrush. Another benefit of this brush is that it's quite non-destructive: it paints off pinches and smoothes out areas as you go.
With the model at a good stage in terms of both shape and proportion, I then moved onto making sure the likeness was there in the expression. I looked at the details of the bust and tried to replicate them in my model. I used the Standard brush a lot to create small holes and to chip the sculpture's surface.
Hair in 3D is always a nightmare, and probably the reason for so many bald characters in games and movies! This being a sculpture, however, the hair was considerably easier. I used a small variety of tools, namely the Rake, Flatten, Clay, Standard and Slash brushes. I masked off the area of the hair and blurred the mask. This meant that any sculpting done on edges of the mask would blend smoothly into the head, just like hair does. Then I attacked the hair with the Rake brush on a high Z- Intensity, and used the Slash brush to add large sections of hair in. Combined, they produced a realistic impression of the bust's hair. It's always important to understand order when sculpting hair; start by creating the underneath and work your way to the outside (Fig.02a & Fig.02b).
With the model complete (Fig.03a & Fig.03b) I tried out various MatCaps to see how the surface reacted to light. It's an important step which helps you to check whether your model is missing any volume in certain areas, or if the holes are not deep enough (Fig.04).
Modifying the preview shadows options can also help with sculpting in the viewport and seeing your model the way it really is. I like to increase the ObjShadow to 100, the length to 17, slope to 1.5, and depth to 0.1. This gives quite harsh lighting conditions and can show depth well (Fig.05).
I sourced some marble textures and began stitching them together, creating a seamless and high resolution marble image. I altered the colour and saturation and painted in some of my own cracks and veins. Using Projection Master, I projected this onto the model in all areas, using the plane3d and radial fade options. With the texture in place, all that was left was the lighting. Lighting either makes or breaks a piece, and I wanted two images: something realistic - a camera shot of the bust in a museum, and an artistic photograph.
I set up the ZBrush lights at a top diagonal left angle, with quite deep and dark shadows. I turned off any ambient lights and created a brand new MatCap to simulate the surface of marble. Things I noticed were a soft, sub surface scattering feel to the stone, crevices picking up reflected light at Fresnel angles, rather than shaded with shadow, and that the reflections could be soft or hard depending on the level of polish. I created a sphere in Max and set up these features in a shader. I then rendered the ball at full screen square with the sphere touching the edges of the image. The image was then used to create a new MatCap in ZBrush.
Using ZBrush DoubleShade material, I loaded Toy Plastic into the first channel, setting no diffuse or ambient contribution - only specular. Then in the second I loaded the MatCap I'd created. This gave a nice dual-layered look. I only really grazed the surface of the power of MatCaps in this image; they are extremely powerful and there are numerous effects that can be achieved by combining them together.
Rendering some simple objects in Max, I heavily blurred them in Photoshop and took them into the ZBrush scene as a background image. I rendered the character on top with depth cue and fog, and the final image was complete. The artistic photograph was rendered in the same way, using a pure black background and black fog (Fig.06 & Fig.07).