Sculpt a stylized Bugs Bunny with ZBrush & XGen
Hello everyone, my name is Yan Blanco and in this making of I will show the creative process for the production of the Bugs Bunny image, my most recent 3D project. The idea came as I thought of some project where I could study XGen. Whenever I can, I study new tools applying knowledge in new personal projects. My intention in this making of is to show how important it was to focus on design concepts in general, to maintain a well-defined silhouette, to understand the model volumes well, to achieve the right expression, and finally to focus on the image as a whole. So I do not want to go into too technical details.
Sketches are a very quick and fun way to test new ideas. If you do not know how to draw, you can do concepts in any way you like, by mixing photos in Photoshop or by blocking shapes in ZBrush, for example. The important thing is to have some process that allows you to explore new ideas quickly and objectively, without sticking to final or technical details. The more fluid the process, the more free you will be to find different things.
Sketches I've been doing while waiting for some renders at work
Once I defined what I was going to create, I started looking for references. In this part I try NOT to select many images, only the main ones that will help me during the process. Design references have served to analyze how the design of Bugs Bunny works, its silhouette and volumes. In reference to the grooming and lookdev, I selected the hair renders that I wanted to achieve in the final result.
I always organize my references in PureRef, as it's very practical and fast
Starting with ZBrush
Now the fun part begins. In ZBrush I started blocking the character, exploring the tired expression I wanted, but always careful not to run too far from the original design. I could have used Dynamesh in this step, but I preferred to separate the volumes into different meshes. This allowed me to have more control of each shape individually, making the process easier.
Initial blocking in ZBrush
Starting with XGen
Before creating Fur, I make new geometries with the Maya 'Modeling Tool Kit' to use as Scalps. Once I have the Scalps made, I make them 'Wrap' to the original model. So whenever I make adjustments to my original model, I'll preserve the fur in the Scalps. To create fur, I created a Splines Description, so I could manually control the direction, shape, and size of the hair. In this project, I separated each Scalp into a different Description (cheeks, chin, eyelids, head, body, and so on).
Paintover in Photoshop
After applying the fur, I created two basic 'Ai Standard Hair' materials for fur (one white and one gray), and applied them in the specific regions of the model (white for cheeks and muzzle, and gray for all the rest). After the first render, I went to Photoshop and made notes in the areas that needed adjustments, and then I did a paintover and Liquify to bring the image closer to what I wanted in the final result. This is a great way to test possibilities in your image quickly and fun.
Finishing the sculpt
Now that I had an idea of what to fix in the model, and how the fur had altered the shapes and silhouette, I came back to ZBrush to make the changes. I decreased the overall volumes, and exaggerated the shapes and the feeling of weight on the cheeks, putting them down. I kept the separated volumes in different objects, because in the final result this did not make a big difference. I also worked the details of the skin, because during the process I decided it would be interesting to reveal some regions without hair. After this step, I exported all the necessary maps (Color, Normal Map and Displacement (32-bits), and the new mesh. For the PolyPaint, I used the custom alphas of ZBrush and cavity masks.
Transferring adjustments with Blend Shapes
After finalizing the model in ZBrush, I imported it into Maya and applied a Blend Shape on the old model. This allowed me to transfer the changes from the new model to the old model, preserving the UVs and shaders I already had. Another interesting detail is that since the Scalps have Wrap in the old model, they followed the geometry when I applied Blend Shape.
Finishing fur in XGen
Now that the model was finished with all the maps applied, I finished the fur. One of the most important things was to keep the guides well-positioned, fine-tuning the hair's direction, and varying its size and rotation where necessary. On the cheeks and chin for example, I used larger guides to give more volume, while in the eyelids and near the nose I left the smaller length. A nice detail that I got from the references of Bugs Bunny was the clumps of the cheek that formed a nice silhouette for the head. So I created a new description to work just in that area.
XGen - masks & modifiers
To make it look old and destroyed I've created density maps on the Scalps. I manually painted regions where I did not want fur to appear, which created an interesting variation on the surface of the model. The modifiers are also very important; I always apply them to generate variation in the fur. Normally I apply 'Clump' and 'Noise', duplicating them and generating different values. For example, I first make bigger Clumps, and then generate smaller ones to break the surface pattern (Noise works well this way too). A nice way to use noise is to create a high frequency one, and use noise masks. This will create some hair strands coming out the general surface.
Substance Painter for the teeth
I created some layers of noise to give variation in color, and I used some brushes to create the wear on the surface. It is interesting to use procedural maps to create texture variation, but only manually painted effects will give a unique look to your model. After finishing the textures, I used Arnold's SSS Randomwalk, with adjustments in the Anisotropy parameter.
For all shaders with SSS, I used Arnold's Randomwalk option, which has a very good result for organic materials. For materials like the nose and the tooth, where I wanted a wet effect, I used the Coat parameter to add a second Specular layer. The hair is 'Ai Standard Hair' with small adjustments of color and roughness.
Tip: Use the SSS Anisotropy parameter to test interesting effects. In the teeth for example, I got a very cool translucent result by increasing Anisotropy.
To illuminate the character I used some area lights, with planes to project shadow and a reflector. I decided to cast shadows on the character to focus more light on the face region, and give a more dramatic appearance in the scene. Another important point was to add specular lights, which helped to highlight areas where the surface was wet, such as the eyes and teeth.
Final comp in Photoshop
To finalize the image, I saved the render in EXR 32-bits to adjust the exposure, and then converted to 16-bits to start the composition. In this project, I rendered the head separately from the body in two versions: one with gray hair and another with white hair – this way I could mix them and use it where I wanted in Photoshop. At this stage I worked in the contrast, colors, and volumes. I also made hand-strokes (using Blend modes) to put color variation in the hair. I like to make a layer in Overlay and use black-and-white tones with a soft brush to reinforce areas of shadow and light in a subtle way. I also applied photos in the composition, like on the tip of the cigarette and the smoke. At the end, I used Liquify and set some regions to improve the silhouette.
Keep workflow easy
Always keep your workflow easy to work with. It is common to need to adjust things in the model during project development, so the more practical it is to fix things, the easier it will be for you to improve your work.
Finished, not perfect
It is common to keep detailing the model for days, and to always find defects in it, but it is important to know how to move on and leave certain things aside. If you are getting tired of your project because of numerous adjustments, know how to identify what is disposable and what is important to change, otherwise you will get tired of the project and will not have any pleasure in completing it.
Final Image - Bugs Bunny after fame