Why did you use ZBrush for these creatures?
It gave us the ability to work in the fast interactive way we needed. As a sculpting tool it really has close links with the world of model making and practical sculpting. Traditionally, the world of CG is often a slow process of working out of context and then bringing elements back together again at the end. ZBrush gives you this in a more interactive way and with an incredible amount of detail that is editable in real-time. This means the creatures could be designed very interactively, often even to the point where directions can be given to an artist as he/she works. For getting design iterations out there this speed is essential.
On the other side we use ZBrush for detailing displacement maps which again historically had been painted out of context and then software rendered to see the result -- quite a counterintuitive way to work. ZBrush means we can visualize what the displacement looks like. Even though we painted up in layers and used a complex shader network to connect all the layers in the renderer, we were still able to see what we painted before all of that.
How many polygons did they come to? How many SubTools?
Well that depends. I think the design sculpts came in around 7-10 million ploys but the final mesh when used to texture and displace was broken up into patches with many SubTools -- each around 4-6 million polys, I think. Sometimes if we generated a displacement map outside of ZBrush we would bring in just one section of the model and divide it up to quite a high level so we could quickly preview that map before sending it out to the renderer.
Were there any particular ZBrush features that came in especially useful?
I think the variety of brushes always give us the control to sculpt in certain ways. SubTools are handy to get you extra detail when and where you need it and the viewport shading is really exceptional.
Both characters are heavily scaled -- something that many artists struggle with getting to look right. What was your technique for getting all that detail and making it look realistic?
It was hard to get the scales to flow in a way that made sense when the Dragon moved. We didn't want it just to be a random thing so a lot of effort was put into making the flow look anatomically correct. We did this by essentially just drawing guide lines on the model in a quick way, then tweaking till we had a final scale layout. This layout was then used as a reference for the actual scales which we did with a mixture of hand and photographic work. We wanted there to be some level of editability later so that if a change came in on something we could trickle it out through all the texture layers without having to repaint much. This is partly why we decided to work on layers in ZBrush and make the final composite of all the layers in our shading network as opposed to bringing all the texture elements into ZBrush at the same time.