How was ZBrush used as a pre-production and concepting tool?
We used ZBrush heavily during the concepting stage as well as when sculpting details. It was particularly useful when we very often had to change the design of the creatures in order to make them work with the shots. We started with digital scans of clay maquettes coming from ADI which gave us a good starting point and also great inspiration getting going. ADI did an amazing job on the concept sculptures.
Initially we were supposed to enhance the practical effects with CGI, however in the end most of the creatures were entirely computer-generated. This was partly due to CG's efficiency for changing designs and animation.
The initial concepting part that we did evolved around the transformations and the many limbs. We used ZBrush to create as many variations as we could for the stages of the transformations and also the many possible looks that limbs could have had when growing out of the human parts.
It was incredibly rapid to sculpt the anatomy and the skin details in ZBrush on some simple geometry and then immediately render them on the plates for concepting. Sometimes we would even simply use MatCaps without a need to render the sculpts. The fast turn around that there was between sculpting and rendering allowed us, the artists, to keep ideas coming. It gave the VFX Supervisor - Jesper Kjolsrud and the Director - Matthijs van Heijningen Jr., a great selection of concepts to work with.
The client, after deciding to replace most of the practical effects with CG, started to request many more variations on the actual concepts of the creatures. So ZBrush was, again, the best tool for the job.
Were there any ZBrush features that really stood out at this phase?
We constantly used Project All when we had to change our geometries. It let us adapt to the new concepts while keeping all the sculpting previously done. We didn't have DynaMesh during concepting, so we used ReMesh All a lot, in combination with ProjectAll.
ZSpheres were used to quickly create and place things like tentacles and fangs.
What really stood out in my opinion is how amazingly responsive the brushes are in the sculpting phase and how versatile ZBrush is in general when we had to solve problems.
Another thing we would use a lot was ZBrush's Turntable feature. Every time we had a new sculpt we would render a turntable of it and send it to the client for immediate feedback. It was quite similar to having a clay maquette on hand. The client was able to look at the sculpt from every angle and point at things he wanted to change.