CGMA Student Project: Canine Anatomy Study

Tsvetelina Zdraveva did a breakdown of her Ibizan Hound Anatomy Study made within CGMA course Sculpting Anatomy: From Animal to Creature and talked about the way classes with Gael Kerchenbaum are organized.

Introduction

My name is Tsvetelina Zdraveva, and I am one half of a Brooklyn-based production studio, Afterman, where I storyboard, illustrate, model and animate the visual stories we tell.

I was born and raised in Bulgaria but moved to the States to pursue a degree in architecture at Rice University in Houston, TX. Throughout my studies, I found myself most drawn to creating 3D visualizations for my architectural environments, and shortly after graduating, I decided to focus entirely on 3D and animation. Since then, I have enjoyed directing and creating a diverse set of video projects, among which were a whimsical short for National Geographic and a PSA for NASA.

Goals

As a transplant into the film industry, I am always on the lookout for resources that can help my work. I found Gael’s CGMA course Sculpting Anatomy: From Animal to Creature while looking for a foundation in animal anatomy and a comprehensive creature sculpting walk-through. I was impressed by the roster of their experienced instructors, and I hoped to gain the secret workflow tips of a talented VFX-industry insider like Gael himself.

How the Class Began

The course kicks off with an incredibly fun discussion on phylogenesis that provides everyone with the skills to sustain their own independent anatomical research. Through the comparative principles that Gael teaches, my peers and I learned to inform our understanding of virtually any creature existing or imagined.

I chose to work on a sculpt of an Ibizan Hound as I was drawn to their unusual capacity for movement and the beautiful pronouncement of their musculature. Each week, before I began sculpting, I would make image reference boards to better understand the forms I’d be working on that specific week. I would markup landmarks to look out for, note any relationships between what I’d already learned and the structures I was studying, and continue to expand my visual library of the Ibizan Hound in movement.

The vibrant Discord classroom where Gael was tirelessly present was extremely helpful in this preparatory stage. It was a dedicated space for us to share our research material, and even months after our term has ended is still a place I visit often and benefit from.

Building the Skeleton in ZBrush

I started with the Hound’s skull, but as I was unable to find the exact photographic reference, I sculpted a general canine skull and then adjusted my mesh to match the proportions of an Ibizan Hound’s head in profile.

The workflow in ZBrush began with a basic sphere that I pushed and pulled with a large Move brush, and subsequently dynameshed to create all the skull cavities. The ClayBuildup and ClayTubes brushes were my favorites for refining the volumes afterward. I feel like with just these two brushes – by adjusting their Imbed value, and sometimes altering their alpha Radial Fade – mostly, I can achieve any shape I am after.

I approached working on the animal’s skeleton in a similar way to the skull. Starting with a typical dog skeleton, I proceeded to adjust its proportions to match the Ibizan Hound reference photographs I had compiled. At this first stage, my most helpful resources were Ellenberger’s and Goldfinger’s anatomies, as well as a number of free online bone scan libraries. Two of my favorite online archives were the Digital Morphology library at the University of Texas at Austin and the collection at the California Academy of Sciences.

Even though I did my best to proportion the bones as closely as possible to the silhouette of the Ibizan Hound, my primary focus at this stage was not to create impeccable proportions. Those kept being adjusted all the way through to the end of the écorché phase. What was most important to me at this point was to make sure each bone had all the necessary surface planes to provide for origin and insertion of superficial muscles. In this exercise, I approached the sculpt of the skeleton as a necessary structure for accurate placement of musculature and not a finished piece on its own.

Building Up the Body

As soon as I built up the skeleton, I began layering superficial muscles starting from the head and making my way inside-out toward the tail. My goal for this class was to gather as much anatomical knowledge as possible, so in many ways, this stage of the sculpt was the most important for me. At this point, I worked primarily from the third volume of the Color Atlas of Veterinary Anatomy and used Ellenberger as a guiding tool along with a selection of greyhound anatomy diagrams by Ernest Thompson Seton from Art Anatomy of Animals.

I modeled each muscle individually, keeping a consistent naming system to help with subtool selection while working. Nick’s Tools is a plugin that has saved my life many times when having to batch rename subtools, and I would gladly recommend it to everyone. I also grouped my subtools to easily include or exclude muscle groups from my viewport. Because muscles are more like sheets of tension than balloons of mass, each layer showcases what lies underneath it. To control the way muscles wrap around what lies under them, I used the ZProject brush.

Each time I created a new subtool, I would Dynamesh it, refine it, and adjust its topology with ZRemesher.

To sculpt the areas around the eyes, nose, and ears, I gathered a lot of close-up photography of Ibizans, dogs, wolves, and even cats. This way, I was able to resolve at the écorché stage both the proportions of the whole figure and the features of the head that would make my sculpt distinguishable as an Ibizan.

Ibizan Hounds have very little fat or fur, so to wrap up my sculpt, my focus was on adding skin, veins, and wrinkles. Exploring the various Smooth brushes inside the ZBrush default folders was a lot of fun here. My favorite were Peaks, Valleys and Directional. As I had gained a mountain of reference material by this point, I found PureRef to be the easiest way to organize and view all photos while working on this layer.

I really enjoyed Gael’s additive method of sculpting from the skeleton out. It not only facilitates more accurate sculptural likeness but allows for a logical transition into posing movement, the next and last stage of this sculpt.

Postures & Presentation

What I love about Ibizans is that they can be both regal and playful. I experimented with a few different poses before settling on the two used for final renders. Both poses were created with Transpose Master and a varying degree of further manual adjustments and resculpting.

To position the final mesh for render, whether to align it with another mesh or to just create a good mesh-to-floor contact, I highly recommend a small script called Positioner. I use it all the time for an accurate and fast arrangement of the things I sculpt in ZBrush.

The renders were created in Octane, which is incredibly fast when paired with a few GeForce 1080Ti’s. A simple waxy texture was applied to the mesh and was lit with three light sources against a simple paper-textured backdrop. The image was then color-corrected in Photoshop and further sweetened by following Gael’s color-correction workflow. I created contrast by stretching the image histogram with a levels adjustment. Then I duplicated the image, isolated and blurred the highlights, and screened this back on top of the composite to create a subtle bloom effect. Lastly, I duplicated the image again, blurred just the red channel, and screened with partial opacity. This last step adds a warm hue to the bloom.

Feedback

Taking part in Gael’s course has been an honor. The lectures alone would have been enough to sustain two courses on their own. Our live Q&A’s additionally covered a wide range of relevant topics a character artist needs to master alongside sculpting: texturing, retopology, rendering, and even grooming.

The class Discord channel really fused the group together and made it easy to share our progress and questions. With Gael’s constant encouragement, we shared resources and kept each other going through each stage of the workflow. Some of the students even live-streamed their progress as they worked (you guys have to check out Denis Udalov’s magnificent gaur and the rigor captured in those process videos).

I have been fueled with a lot of new creative ideas to work on, and I cannot wait to share my next creature with all of you. Thank you so much to Gael for your generosity, commitment, and knowledge, and to everyone at 80 Level for the thoughtful questions and the opportunity to talk about my work with you.

Tsvetelina Zdraveva, 3D Modeler & Texture Artist at Afterman

Interview conducted by Daria Loginova